Hepatocellular carcinoma (HCC) is the commonest primary malignant cancer of the liver in the world. Given that the burden of chronic liver disease is expected to rise owing to increasing rates of alcoholism, hepatitis...Hepatocellular carcinoma (HCC) is the commonest primary malignant cancer of the liver in the world. Given that the burden of chronic liver disease is expected to rise owing to increasing rates of alcoholism, hepatitis B and C prevalence and obesity-related fatty liver disease, it is expected that the incidence of HCC will also increase in the foreseeable future. This article summarizes the international epidemiology, the risk factors and the pathogenesis of HCC, including the roles of viral hepatitis, toxins, such as alcohol and aflatoxin, and insulin resistance.展开更多
Approximately 20% of patients with acute pancreatitis develop a severe disease associated with complications and high risk of mortality. The purpose of this study is to review pathogenesis and prognostic factors of se...Approximately 20% of patients with acute pancreatitis develop a severe disease associated with complications and high risk of mortality. The purpose of this study is to review pathogenesis and prognostic factors of severe acute pancreatitis （SAP）. An extensive medline search was undertaken with focusing on pathogenesis, complications and prognostic evaluation of SAP. Cytokines and other inflammatory markers play a major role in the pathogenesis and course of SAP and can be used as prognostic markers in its early phase. Other markers such as simple prognostic scores have been found to be as e^ective as multifactorial scoring systems （MFSS） at 48 h with the advantage of simplicity, efficacy, low cost, accuracy and early prediction of SAP. Recently, several laboratory markers including hematocrit, blood urea nitrogen （BUN）, creatinine, matrix metalloproteinase-9 （MMP-9） and serum amyloid A （SAA） have been used as early predictors of severity within the first 24 h. The last few years have witnessed a tremendous progress in understanding the pathogenesis and predicting the outcome of SAP. In this review we classified the prognostic markers into predictors of severity, pancreatic necrosis （PN）, infected PN （IPN） and mortality.展开更多
AIM: To compare the benefi cial effects of early enteral nutrition (EN) with prebiotic fiber supplementation in patients with severe acute pancreatitis (AP).METHODS: Thirty consecutive patients with severe AP, who req...AIM: To compare the benefi cial effects of early enteral nutrition (EN) with prebiotic fiber supplementation in patients with severe acute pancreatitis (AP).METHODS: Thirty consecutive patients with severe AP, who required stoppage of oral feeding for 48 h, were randomly assigned to nasojejunal EN with or without prebiotics. APACHE Ⅱ score, Balthazar’s CT score and CRP were assessed daily during the study period.RESULTS: The median duration of hospital stay was shorter in the study group [10 ± 4 (8-14) d vs 15 ± 6 (7-26) d] (P < 0.05). The median value of days in intensive care unit was also similar in both groups [6 ± 2 (5-8) d vs 6 ± 2 (5-7) d]. The median duration of EN was 8 ± 4 (6-12) d vs 10 ± 4 (6-13) d in the study and control groups, respectively (P > 0.05). Deaths occurred in 6 patients (20%), 2 in the study group and 4 in the control group. The mean duration of APACHE Ⅱ normalization (APACHE Ⅱ score < 8) was shorter in the study group than in the control group (4 ± 2 d vs 6.5 ± 3 d, P < 0.05). The mean duration of CRP normalization was also shorter in the study group than in the control group (7 ± 2 d vs 10 ± 3 d, P < 0.05).CONCLUSION: Nasojejunal EN with prebiotic fiber supplementation in severe AP improves hospital stay, duration nutrition therapy, acute phase response and overall complications compared to standard EN therapy.展开更多
Biliary tract complications are the most common complications after liver transplantation.These complications are encountered more commonly as a result of increased number of liver transplantations and the prolonged s...Biliary tract complications are the most common complications after liver transplantation.These complications are encountered more commonly as a result of increased number of liver transplantations and the prolonged survival of transplant patients.Biliary complications remain a major source of morbidity in liver transplant patients,with an incidence of 5%-32%.Post liver transplantation biliary complications include strictures(anastomotic and non-anastomotic),leaks,stones,sphincter of Oddi dysfunction,and recurrence of primary biliary disease such as primary sclerosing cholangitis and primary biliary cirrhosis.The risk of occurrence of a specific biliary complication is related to the type of biliary reconstruction performed at the time of liver transplantation.In this article we seek to review the major biliary complications and their relation to the type of biliary reconstruction performed at the time of liver tranplantation.展开更多
AIM： To evaluate the antibacterial activity of Sapindus mukorossi （S. mukorossl） and Rheum emodi （R. emodl）. METHODS： Powders of S. mukorossi and R. emodi were extracted successively with petroleum ether, benzen...AIM： To evaluate the antibacterial activity of Sapindus mukorossi （S. mukorossl） and Rheum emodi （R. emodl）. METHODS： Powders of S. mukorossi and R. emodi were extracted successively with petroleum ether, benzene, chloroform and ethanol and were concentrated in vacuum. The disk diffusion method was used for in vitro studies and in vivo studies were performed on male Wister rats. Thirty resistant clinical isolates of H pylon, as determined by their antibiotic sensitivity patterns by E-test, along with two Gram ＋ve （S. aureus, B. subtilis） and two Gram -ve （E. coli, P. vugaris） organisms were screened for their susceptibility patterns against these extracts. RESULTS： In our screening, all 30 resistant isolates and the other four organisms （two Gram ＋ve S. aureus, B. subtilis and two Gram -ve, E. coli, P. vugaris） were sensitive to the test compounds. It was found that ethanol and chloroform extracts of S. mukorossi and ethanol and benzene extracts of R. emodi inhibited Hpylori at very low concentrations, In the in vitro study, the isolates showed a considerable zone of inhibition at very low concentrations （10 μg/mL） for both the extracts. In the in vivo study, the H pylori infection was cleared with minimal doses of extracts of S. mukorossi （2.5 mg/mL） and R. emodi （3.0 mg/mL） given orally for seven days. CONCLUSION： We can conclude from this study that the extracts of S. mukorossi and R. emodi inhibited the growth of pylori in vitro and, in in vivo studies, the H pylori infection cleared within seven days at very low concentrations. We also found that H pylori did not acquire resistance against these herbal extracts even after 10 consecutive passages.展开更多
A microRNA expression screen was performed analyzing 157 different microRNAs in laser-microdissected tissues from benign melanocytic nevi （n = 10） and primary malignant melanomas （n = 10）, using quantitative real-...A microRNA expression screen was performed analyzing 157 different microRNAs in laser-microdissected tissues from benign melanocytic nevi （n = 10） and primary malignant melanomas （n = 10）, using quantitative real-time PCR. Differential expression was found for 72 microRNAs. Members of the let-7 family of microRNAs were significantly downregulated in primary melanomas as compared with benign nevi, suggestive for a possible role of these molecules as tumor suppressors in malignant melanoma. Interestingly, similar findings had been described for lung and colon cancer. Overexpression of let-7b in melanoma cells in vitro downregulated the expression of cyclins D1, D3, and A, and cyclin-dependent kinase （Cdk） 4, all of which had been described to play a role in melanoma development. The effect oflet-7b on protein expression was due to targeting of 3＇-untranslated regions （3＇UTRs） of individual mRNAs, as exemplified by reporter gene analyses for cyclin D1. In line with its downmodulating effects on cell cycle regulators, let-7b inhibited cell cycle progression and anchorage-independent growth of melanoma cells. Taken together, these findings not only point to new regulatory mechanisms of early melanoma development, but also may open avenues for future targeted therapies of this tumor.展开更多
Chinese super hybrid rice breeding project has developed many new varieties with great yield potential. It is controversial which yield component should be emphasized in super hybrid rice production. The present study...Chinese super hybrid rice breeding project has developed many new varieties with great yield potential. It is controversial which yield component should be emphasized in super hybrid rice production. The present study was conducted to compare super hybrid rice with common hybrid and super inbred rice and analyze contributions of yield components to grain yield of super hybrid rice under experimental conditions, and evaluate relationships between grain yield and yield components of super hybrid rice in farmer’s paddy fields. Field experiments were done in Changsha, Guidong, and Nanxian, Hunan Province, China, from 2007 to 2009. Eight super hybrid varieties, one common hybrid variety, and one super inbred variety were grown in each location and year. Rice production investigation was undertaken in high-yielding （Guidong）, moderate-yielding （Nanxian）, and low-yielding （Ningxiang） regions of Hunan Province, China, in 2009. Grain yield and yield components were measured in both the field experiments and rice production investigation. Super hybrid rice varieties outyielded common hybrid and super inbred varieties across three locations and years. Yield potential has been increased by 11.4% in super hybrid rice varieties compared with common and super inbred varieties. The higher yield of super hybrid varieties was attributed to improvement in panicle size. Panicles per m2 had the highest positive contribution to grain yield with the exception under yield level of 10.0 to 12.0 t ha-1, and was positively related to grain yield in farmer’s field at all of the high-, moderate-, and low-yielding regions. Our study suggests that panicle per m2 ought to be emphasized in super hybrid rice production.展开更多
Digital farming is the practice of modern technologies such as sensors,robotics,and data analysis for shifting from tedious operations to continuously automated processes.This paper reviews some of the latest achievem...Digital farming is the practice of modern technologies such as sensors,robotics,and data analysis for shifting from tedious operations to continuously automated processes.This paper reviews some of the latest achievements in agricultural robotics,specifically those that are used for autonomous weed control,field scouting,and harvesting.Object identification,task planning algorithms,digitalization and optimization of sensors are highlighted as some of the facing challenges in the context of digital farming.The concepts of multi-robots,human-robot collaboration,and environment reconstruction from aerial images and ground-based sensors for the creation of virtual farms were highlighted as some of the gateways of digital farming.It was shown that one of the trends and research focuses in agricultural field robotics is towards building a swarm of small scale robots and drones that collaborate together to optimize farming inputs and reveal denied or concealed information.For the case of robotic harvesting,an autonomous framework with several simple axis manipulators can be faster and more efficient than the currently adapted professional expensive manipulators.While robots are becoming the inseparable parts of the modern farms,our conclusion is that it is not realistic to expect an entirely automated farming system in the future.展开更多
AIM: Bezoars (BZ) are the most common foreign bodies of gastrointestinal tract. Clinical manifestations vary depending on the location of BZ from no symptoms to acute abdominal syndrome. When located in small bowel, t...AIM: Bezoars (BZ) are the most common foreign bodies of gastrointestinal tract. Clinical manifestations vary depending on the location of BZ from no symptoms to acute abdominal syndrome. When located in small bowel, they frequently cause small bowel obstruction (SBO). We aimed to present our experience by reviewing literature.METHODS: Thirty-four patients with gastrointestinal BZ were presented. The data were collected from hospital records and analyzed retrospectively. Morbidity and mortality rates were statistically analyzed between the subgroups according to SBO and endoscopic or surgical treatment modalities.RESULTS: The 34 patients had phytobezoars (PBZ). Two patients with mental retardation and trichotillomania had trichobezoars (TBZ). More than half of them (55.88%) had previous gastric surgery. Also most of them had small bowel bezoars resulting in obstruction. Surgical and endoscopic morbidity rates were 32.14% and 14.28% respectively.The total morbidity rate of this study was 29.41%. Four patients in surgically treated group died. There was no death in endoscopically treated group. The total and surgical mortality rates were 11.76% and 14.28% respectively. The differences in morbidity and mortality rates between the subgroups were not statistically significant.CONCLUSION: BZ are commonly seen in stomach and small intestine. SBO is the most common complication.When uncomplicated, endoscopic or surgical removal can be applied easily.展开更多
AIM: To study the hepatoprotective capacity of Sapindus mukorossi (S. mukorossi) and Rheum emodi (R. emodi) extracts in CCl4 treated male rats. METHODS: The dried powder of S. mukorossi and R. emodi was extracted succ...AIM: To study the hepatoprotective capacity of Sapindus mukorossi (S. mukorossi) and Rheum emodi (R. emodi) extracts in CCl4 treated male rats. METHODS: The dried powder of S. mukorossi and R. emodi was extracted successively with petroleum ether, benzene, chloroform, and ethanol and concentrated in vacuum. Primary rat hepatocyte monolayer cultures were used for in vitro studies. In vivo, the hepatoprotective capacity of the extract of the fruit pericarp of S. mukorossi and the rhizomes of R. emodi was analyzed in liver injured CCl4-treated male rats. RESULTS: In vitro: primary hepatocytes monolayer cultures were treated with CCl4 and extracts of S. mukorossi & R. emodi. A protective activity could be demonstrated in the CCl4 damaged primary monolayer culture. In vivo : extracts of the fruit pericarp of S. mukorossi (2.5 mg/mL) and rhizomes of R. emodi (3.0 mg/mL) were found to have protective properties in rats with CCl4 induced liver damage as judged from serum marker enzyme activities. CONCLUSION: The extracts of S. mukorossi and R. emodi do have a protective capacity both in vitro on primary hepatocytes cultures and in in vivo in a rat model of CCl4 mediated liver injury.展开更多
Liver resection for hepatocellular carcinoma(HCC)is currently known to be a safer procedure than it was before because of technical advances and improvement in postoperative patient management and remains the first-li...Liver resection for hepatocellular carcinoma(HCC)is currently known to be a safer procedure than it was before because of technical advances and improvement in postoperative patient management and remains the first-line treatment for HCC in compensated cirrhosis.The aim of this review is to assess current indications,advantages and limits of laparoscopic surgery for HCC resections.We also discussed the possible evolution of this surgical approach in parallel with new technologies.展开更多
Physical traumas are tragic and multifaceted injuries that suddenly threaten life.Although it is the third most common cause of death in all age groups,one out of four trauma patients die due to thoracic injury or its...Physical traumas are tragic and multifaceted injuries that suddenly threaten life.Although it is the third most common cause of death in all age groups,one out of four trauma patients die due to thoracic injury or its complications.Blunt injuries constitute the majority of chest trauma.This indicates the im porta nee of chest trauma among all traumas.Blunt chest trauma is usually caused by motor vehicle accident,falling from height,blunt instrument injury and physical assault.As a result of chest trauma,many injuries may occur,such as pulm onary injuries,and these require urge nt in terve ntion.Chest wall and pulmonary injuries range from rib fractures to flail chest,pneumothorax to hemothorax and pulmonary contusion to tracheobronchial injuries.Following these injuries,patients may present with a simple dyspnea or even respiratory arrest.For such patie nt,it is imports nt to understa nd the treatme nt logic and to take a multidisciplinary approach to treat the pulmonary and chest wall injuries.This is because only 10%of thoracic trauma patients require surgical operation and the remaining 90%can be treated with simple methods such as appropriate airway,oxygen support,maneuvers,volume support and tube thoracostomy.Adequate pain control in chest trauma is sometimes the most basic and best treatment.With definite diagnosis,the morbidity and mortality can be significantly reduced by simple treatment methods.展开更多
Greenhouse cultivation has evolved from simple covered rows of open-fields crops to highly sophisticated controlled environment agriculture(CEA)facilities that projected the image of plant factories for urban agricult...Greenhouse cultivation has evolved from simple covered rows of open-fields crops to highly sophisticated controlled environment agriculture(CEA)facilities that projected the image of plant factories for urban agriculture.The advances and improvements in CEA have promoted the scientific solutions for the efficient production of plants in populated cities and multi-story buildings.Successful deployment of CEA for urban agriculture requires many components and subsystems,as well as the understanding of the external influencing factors that should be systematically considered and integrated.This review is an attempt to highlight some of the most recent advances in greenhouse technology and CEA in order to raise the awareness for technology transfer and adaptation,which is necessary for a successful transition to urban agriculture.This study reviewed several aspects of a high-tech CEA system including improvements in the frame and covering materials,environment perception and data sharing,and advanced microclimate control and energy optimization models.This research highlighted urban agriculture and its derivatives,including vertical farming,rooftop greenhouses and plant factories which are the extensions of CEA and have emerged as a response to the growing population,environmental degradation,and urbanization that are threatening food security.Finally,several opportunities and challenges have been identified in implementing the integrated CEA and vertical farming for urban agriculture.展开更多
ESPITE the strong association between gastroesophageal reflux disease （GERD） and asthma has been undisputedly established and widely recognized by experts in advanced countries. Yet few topics in medicine are as con...ESPITE the strong association between gastroesophageal reflux disease （GERD） and asthma has been undisputedly established and widely recognized by experts in advanced countries. Yet few topics in medicine are as controversial as the causal relationship between GERD and asthma： some argue that GERD causes asthma, while others think the other way around is true, still quite a few believe that bronchodilator medications are to blame. This controversy continues to be a conundrum or more piece of the puzzle.1 We would like to share two thoughts which might be a belated revelation with scholars and experts and invite them for further cooperative studies： the GERD-derived respiratory distress is not asthma, but GERD pure and simple; and the pathogenesis of respiratory distress is not asthma, but laryngotracheal irritation/spasm/suffocation.展开更多
Optical wireless communication(OWC)using the ultra-broad spectrum of the visible-to-ultraviolet(UV)wavelength region remains a vital field of research for mitigating the saturated bandwidth of radio-frequency(RF)commu...Optical wireless communication(OWC)using the ultra-broad spectrum of the visible-to-ultraviolet(UV)wavelength region remains a vital field of research for mitigating the saturated bandwidth of radio-frequency(RF)communication.However,the lack of an efficient UV photodetection methodology hinders the development of UV-based communication.The key technological impediment is related to the low UV-photon absorption in existing silicon photodetectors,which offer low-cost and mature platforms.To address this technology gap,we report a hybrid Sibased photodetection scheme by incorporating CsPbBr_(3) perovskite nanocrystals(NCs)with a high photoluminescence quantum yield(PLQY)and a fast photoluminescence(PL)decay time as a UV-to-visible colourconverting layer for high-speed solar-blind UV communication.The facile formation of drop-cast CsPbBr_(3) perovskite NCs leads to a high PLQY of up to ~73% and strong absorption in the UV region.With the addition of the NC layer,a nearly threefold improvement in the responsivity and an increase of ~25% in the external quantum efficiency(EQE)of the solar-blind region compared to a commercial silicon-based photodetector were observed.Moreover,timeresolved photoluminescence measurements demonstrated a decay time of 4.5 ns under a 372-nm UV excitation source,thus elucidating the potential of this layer as a fast colour-converting layer.A high data rate of up to 34 Mbps in solar-blind communication was achieved using the hybrid CsPbBr_(3)-silicon photodetection scheme in conjunction with a 278-nm UVC light-emitting diode(LED).These findings demonstrate the feasibility of an integrated high-speed photoreceiver design of a composition-tuneable perovskite-based phosphor and a low-cost silicon-based photodetector for UV communication.展开更多
Adsorption is an important process in wastewater treatment,and conversion of waste materials to adsorbent offers a solution to high material cost related to the use of commercial activated carbon.This study investigat...Adsorption is an important process in wastewater treatment,and conversion of waste materials to adsorbent offers a solution to high material cost related to the use of commercial activated carbon.This study investigated the adsorption behaviour of Reactive Black 5（RB5）and methylene blue（MB）onto activated carbon produced from textile sludge（TSAC）.The activated carbon was synthesized through chemical activation of precursor followed with carbonization at 650℃ under nitrogen flow.Effects of time（0–200 min）,pH（2–10）,temperature（25–60℃）,initial dye concentration（0–200 mg·L^-1）,and adsorbent dosage（0.01–0.15 g）on dye removal efficiency were investigated.Preliminary screening revealed that TSAC synthesized via H2SO4activation showed higher adsorption behaviour than TSAC activated by KCl and ZnCl2.The adsorption capacity of TSAC was found to be 11.98 mg·g^-1（RB5）and 13.27 mg·g^-1（MB）,and is dependent on adsorption time and initial dye concentration.The adsorption data for both dyes were well fitted to Freundlich isotherm model which explains the heterogeneous nature of TSAC surface.The dye adsorption obeyed pseudo-second order kinetic model,thus chemisorption was the controlling step.This study reveals potential of textile sludge in removal of dyes from aqueous solution,and further studies are required to establish the applicability of the synthesized adsorbent for the treatment of waste water containing toxic dyes from textile industry.展开更多
Mobile ad-hoc networks （MANETs） and wireless sensor networks （WSNs） have gained remarkable apprecia- tion and technological development over the last few years. Despite ease of deployment, tremendous applications ...Mobile ad-hoc networks （MANETs） and wireless sensor networks （WSNs） have gained remarkable apprecia- tion and technological development over the last few years. Despite ease of deployment, tremendous applications and significant advantages, security has always been a challeng- ing issue due to the nature of environments in which nodes operate. Nodes＇ physical capture, malicious or selfish behav- ior cannot be detected by traditional security schemes. Trust and reputation based approaches have gained global recog- nition in providing additional means of security for decision making in sensor and ad-hoc networks. This paper provides an extensive literature review of trust and reputation based models both in sensor and ad-hoc networks. Based on the mechanism of trust establishment, we categorize the state- of-the-art into two groups namely node-centric trust mod- els and system-centric trust models. Based on trust evidence, initialization, computation, propagation and weight assign- ments, we evaluate the efficacy of the existing schemes. Fi- nally, we conclude our discussion with identification of some unresolved issues in pursuit of trust and reputation manage- ment.展开更多
基金The NIHR Biomedical Research Centre funding scheme and the following for authors’ funding and support: AIG is funded by a scholarship from the Egyptian Government SAK is supported by a grant from the Higher Education Funding Council for England (HEFCE)+5 种基金 SDTR is funded by grants from the British Medical Research Council (MRC), London, United Kingdomthe British Engineering, Physics and Science Research Council (EPSRC), Swindon, United Kingdomthe Alan Morement Memorial Fund AMMF, Essex, UK Broad Foundation, Los Angeles, United StatesPfizer Global Research and Development Inc, Sandwich, United Kingdom GlaxoSmithKline, Ware, United Kingdom
文摘Hepatocellular carcinoma (HCC) is the commonest primary malignant cancer of the liver in the world. Given that the burden of chronic liver disease is expected to rise owing to increasing rates of alcoholism, hepatitis B and C prevalence and obesity-related fatty liver disease, it is expected that the incidence of HCC will also increase in the foreseeable future. This article summarizes the international epidemiology, the risk factors and the pathogenesis of HCC, including the roles of viral hepatitis, toxins, such as alcohol and aflatoxin, and insulin resistance.
文摘Approximately 20% of patients with acute pancreatitis develop a severe disease associated with complications and high risk of mortality. The purpose of this study is to review pathogenesis and prognostic factors of severe acute pancreatitis （SAP）. An extensive medline search was undertaken with focusing on pathogenesis, complications and prognostic evaluation of SAP. Cytokines and other inflammatory markers play a major role in the pathogenesis and course of SAP and can be used as prognostic markers in its early phase. Other markers such as simple prognostic scores have been found to be as e^ective as multifactorial scoring systems （MFSS） at 48 h with the advantage of simplicity, efficacy, low cost, accuracy and early prediction of SAP. Recently, several laboratory markers including hematocrit, blood urea nitrogen （BUN）, creatinine, matrix metalloproteinase-9 （MMP-9） and serum amyloid A （SAA） have been used as early predictors of severity within the first 24 h. The last few years have witnessed a tremendous progress in understanding the pathogenesis and predicting the outcome of SAP. In this review we classified the prognostic markers into predictors of severity, pancreatic necrosis （PN）, infected PN （IPN） and mortality.
文摘AIM: To compare the benefi cial effects of early enteral nutrition (EN) with prebiotic fiber supplementation in patients with severe acute pancreatitis (AP).METHODS: Thirty consecutive patients with severe AP, who required stoppage of oral feeding for 48 h, were randomly assigned to nasojejunal EN with or without prebiotics. APACHE Ⅱ score, Balthazar’s CT score and CRP were assessed daily during the study period.RESULTS: The median duration of hospital stay was shorter in the study group [10 ± 4 (8-14) d vs 15 ± 6 (7-26) d] (P < 0.05). The median value of days in intensive care unit was also similar in both groups [6 ± 2 (5-8) d vs 6 ± 2 (5-7) d]. The median duration of EN was 8 ± 4 (6-12) d vs 10 ± 4 (6-13) d in the study and control groups, respectively (P > 0.05). Deaths occurred in 6 patients (20%), 2 in the study group and 4 in the control group. The mean duration of APACHE Ⅱ normalization (APACHE Ⅱ score < 8) was shorter in the study group than in the control group (4 ± 2 d vs 6.5 ± 3 d, P < 0.05). The mean duration of CRP normalization was also shorter in the study group than in the control group (7 ± 2 d vs 10 ± 3 d, P < 0.05).CONCLUSION: Nasojejunal EN with prebiotic fiber supplementation in severe AP improves hospital stay, duration nutrition therapy, acute phase response and overall complications compared to standard EN therapy.
文摘Biliary tract complications are the most common complications after liver transplantation.These complications are encountered more commonly as a result of increased number of liver transplantations and the prolonged survival of transplant patients.Biliary complications remain a major source of morbidity in liver transplant patients,with an incidence of 5%-32%.Post liver transplantation biliary complications include strictures(anastomotic and non-anastomotic),leaks,stones,sphincter of Oddi dysfunction,and recurrence of primary biliary disease such as primary sclerosing cholangitis and primary biliary cirrhosis.The risk of occurrence of a specific biliary complication is related to the type of biliary reconstruction performed at the time of liver transplantation.In this article we seek to review the major biliary complications and their relation to the type of biliary reconstruction performed at the time of liver tranplantation.
文摘AIM： To evaluate the antibacterial activity of Sapindus mukorossi （S. mukorossl） and Rheum emodi （R. emodl）. METHODS： Powders of S. mukorossi and R. emodi were extracted successively with petroleum ether, benzene, chloroform and ethanol and were concentrated in vacuum. The disk diffusion method was used for in vitro studies and in vivo studies were performed on male Wister rats. Thirty resistant clinical isolates of H pylon, as determined by their antibiotic sensitivity patterns by E-test, along with two Gram ＋ve （S. aureus, B. subtilis） and two Gram -ve （E. coli, P. vugaris） organisms were screened for their susceptibility patterns against these extracts. RESULTS： In our screening, all 30 resistant isolates and the other four organisms （two Gram ＋ve S. aureus, B. subtilis and two Gram -ve, E. coli, P. vugaris） were sensitive to the test compounds. It was found that ethanol and chloroform extracts of S. mukorossi and ethanol and benzene extracts of R. emodi inhibited Hpylori at very low concentrations, In the in vitro study, the isolates showed a considerable zone of inhibition at very low concentrations （10 μg/mL） for both the extracts. In the in vivo study, the H pylori infection was cleared with minimal doses of extracts of S. mukorossi （2.5 mg/mL） and R. emodi （3.0 mg/mL） given orally for seven days. CONCLUSION： We can conclude from this study that the extracts of S. mukorossi and R. emodi inhibited the growth of pylori in vitro and, in in vivo studies, the H pylori infection cleared within seven days at very low concentrations. We also found that H pylori did not acquire resistance against these herbal extracts even after 10 consecutive passages.
文摘A microRNA expression screen was performed analyzing 157 different microRNAs in laser-microdissected tissues from benign melanocytic nevi （n = 10） and primary malignant melanomas （n = 10）, using quantitative real-time PCR. Differential expression was found for 72 microRNAs. Members of the let-7 family of microRNAs were significantly downregulated in primary melanomas as compared with benign nevi, suggestive for a possible role of these molecules as tumor suppressors in malignant melanoma. Interestingly, similar findings had been described for lung and colon cancer. Overexpression of let-7b in melanoma cells in vitro downregulated the expression of cyclins D1, D3, and A, and cyclin-dependent kinase （Cdk） 4, all of which had been described to play a role in melanoma development. The effect oflet-7b on protein expression was due to targeting of 3＇-untranslated regions （3＇UTRs） of individual mRNAs, as exemplified by reporter gene analyses for cyclin D1. In line with its downmodulating effects on cell cycle regulators, let-7b inhibited cell cycle progression and anchorage-independent growth of melanoma cells. Taken together, these findings not only point to new regulatory mechanisms of early melanoma development, but also may open avenues for future targeted therapies of this tumor.
基金support was provided by the Earmarked Fund for Modern Agro-Industry Technology of Chinathe Super Rice Project of Ministry of Agriculture of China
文摘Chinese super hybrid rice breeding project has developed many new varieties with great yield potential. It is controversial which yield component should be emphasized in super hybrid rice production. The present study was conducted to compare super hybrid rice with common hybrid and super inbred rice and analyze contributions of yield components to grain yield of super hybrid rice under experimental conditions, and evaluate relationships between grain yield and yield components of super hybrid rice in farmer’s paddy fields. Field experiments were done in Changsha, Guidong, and Nanxian, Hunan Province, China, from 2007 to 2009. Eight super hybrid varieties, one common hybrid variety, and one super inbred variety were grown in each location and year. Rice production investigation was undertaken in high-yielding （Guidong）, moderate-yielding （Nanxian）, and low-yielding （Ningxiang） regions of Hunan Province, China, in 2009. Grain yield and yield components were measured in both the field experiments and rice production investigation. Super hybrid rice varieties outyielded common hybrid and super inbred varieties across three locations and years. Yield potential has been increased by 11.4% in super hybrid rice varieties compared with common and super inbred varieties. The higher yield of super hybrid varieties was attributed to improvement in panicle size. Panicles per m2 had the highest positive contribution to grain yield with the exception under yield level of 10.0 to 12.0 t ha-1, and was positively related to grain yield in farmer’s field at all of the high-, moderate-, and low-yielding regions. Our study suggests that panicle per m2 ought to be emphasized in super hybrid rice production.
文摘Digital farming is the practice of modern technologies such as sensors,robotics,and data analysis for shifting from tedious operations to continuously automated processes.This paper reviews some of the latest achievements in agricultural robotics,specifically those that are used for autonomous weed control,field scouting,and harvesting.Object identification,task planning algorithms,digitalization and optimization of sensors are highlighted as some of the facing challenges in the context of digital farming.The concepts of multi-robots,human-robot collaboration,and environment reconstruction from aerial images and ground-based sensors for the creation of virtual farms were highlighted as some of the gateways of digital farming.It was shown that one of the trends and research focuses in agricultural field robotics is towards building a swarm of small scale robots and drones that collaborate together to optimize farming inputs and reveal denied or concealed information.For the case of robotic harvesting,an autonomous framework with several simple axis manipulators can be faster and more efficient than the currently adapted professional expensive manipulators.While robots are becoming the inseparable parts of the modern farms,our conclusion is that it is not realistic to expect an entirely automated farming system in the future.
文摘AIM: Bezoars (BZ) are the most common foreign bodies of gastrointestinal tract. Clinical manifestations vary depending on the location of BZ from no symptoms to acute abdominal syndrome. When located in small bowel, they frequently cause small bowel obstruction (SBO). We aimed to present our experience by reviewing literature.METHODS: Thirty-four patients with gastrointestinal BZ were presented. The data were collected from hospital records and analyzed retrospectively. Morbidity and mortality rates were statistically analyzed between the subgroups according to SBO and endoscopic or surgical treatment modalities.RESULTS: The 34 patients had phytobezoars (PBZ). Two patients with mental retardation and trichotillomania had trichobezoars (TBZ). More than half of them (55.88%) had previous gastric surgery. Also most of them had small bowel bezoars resulting in obstruction. Surgical and endoscopic morbidity rates were 32.14% and 14.28% respectively.The total morbidity rate of this study was 29.41%. Four patients in surgically treated group died. There was no death in endoscopically treated group. The total and surgical mortality rates were 11.76% and 14.28% respectively. The differences in morbidity and mortality rates between the subgroups were not statistically significant.CONCLUSION: BZ are commonly seen in stomach and small intestine. SBO is the most common complication.When uncomplicated, endoscopic or surgical removal can be applied easily.
文摘AIM: To study the hepatoprotective capacity of Sapindus mukorossi (S. mukorossi) and Rheum emodi (R. emodi) extracts in CCl4 treated male rats. METHODS: The dried powder of S. mukorossi and R. emodi was extracted successively with petroleum ether, benzene, chloroform, and ethanol and concentrated in vacuum. Primary rat hepatocyte monolayer cultures were used for in vitro studies. In vivo, the hepatoprotective capacity of the extract of the fruit pericarp of S. mukorossi and the rhizomes of R. emodi was analyzed in liver injured CCl4-treated male rats. RESULTS: In vitro: primary hepatocytes monolayer cultures were treated with CCl4 and extracts of S. mukorossi & R. emodi. A protective activity could be demonstrated in the CCl4 damaged primary monolayer culture. In vivo : extracts of the fruit pericarp of S. mukorossi (2.5 mg/mL) and rhizomes of R. emodi (3.0 mg/mL) were found to have protective properties in rats with CCl4 induced liver damage as judged from serum marker enzyme activities. CONCLUSION: The extracts of S. mukorossi and R. emodi do have a protective capacity both in vitro on primary hepatocytes cultures and in in vivo in a rat model of CCl4 mediated liver injury.
文摘Liver resection for hepatocellular carcinoma(HCC)is currently known to be a safer procedure than it was before because of technical advances and improvement in postoperative patient management and remains the first-line treatment for HCC in compensated cirrhosis.The aim of this review is to assess current indications,advantages and limits of laparoscopic surgery for HCC resections.We also discussed the possible evolution of this surgical approach in parallel with new technologies.
文摘Physical traumas are tragic and multifaceted injuries that suddenly threaten life.Although it is the third most common cause of death in all age groups,one out of four trauma patients die due to thoracic injury or its complications.Blunt injuries constitute the majority of chest trauma.This indicates the im porta nee of chest trauma among all traumas.Blunt chest trauma is usually caused by motor vehicle accident,falling from height,blunt instrument injury and physical assault.As a result of chest trauma,many injuries may occur,such as pulm onary injuries,and these require urge nt in terve ntion.Chest wall and pulmonary injuries range from rib fractures to flail chest,pneumothorax to hemothorax and pulmonary contusion to tracheobronchial injuries.Following these injuries,patients may present with a simple dyspnea or even respiratory arrest.For such patie nt,it is imports nt to understa nd the treatme nt logic and to take a multidisciplinary approach to treat the pulmonary and chest wall injuries.This is because only 10%of thoracic trauma patients require surgical operation and the remaining 90%can be treated with simple methods such as appropriate airway,oxygen support,maneuvers,volume support and tube thoracostomy.Adequate pain control in chest trauma is sometimes the most basic and best treatment.With definite diagnosis,the morbidity and mortality can be significantly reduced by simple treatment methods.
文摘Greenhouse cultivation has evolved from simple covered rows of open-fields crops to highly sophisticated controlled environment agriculture(CEA)facilities that projected the image of plant factories for urban agriculture.The advances and improvements in CEA have promoted the scientific solutions for the efficient production of plants in populated cities and multi-story buildings.Successful deployment of CEA for urban agriculture requires many components and subsystems,as well as the understanding of the external influencing factors that should be systematically considered and integrated.This review is an attempt to highlight some of the most recent advances in greenhouse technology and CEA in order to raise the awareness for technology transfer and adaptation,which is necessary for a successful transition to urban agriculture.This study reviewed several aspects of a high-tech CEA system including improvements in the frame and covering materials,environment perception and data sharing,and advanced microclimate control and energy optimization models.This research highlighted urban agriculture and its derivatives,including vertical farming,rooftop greenhouses and plant factories which are the extensions of CEA and have emerged as a response to the growing population,environmental degradation,and urbanization that are threatening food security.Finally,several opportunities and challenges have been identified in implementing the integrated CEA and vertical farming for urban agriculture.
文摘ESPITE the strong association between gastroesophageal reflux disease （GERD） and asthma has been undisputedly established and widely recognized by experts in advanced countries. Yet few topics in medicine are as controversial as the causal relationship between GERD and asthma： some argue that GERD causes asthma, while others think the other way around is true, still quite a few believe that bronchodilator medications are to blame. This controversy continues to be a conundrum or more piece of the puzzle.1 We would like to share two thoughts which might be a belated revelation with scholars and experts and invite them for further cooperative studies： the GERD-derived respiratory distress is not asthma, but GERD pure and simple; and the pathogenesis of respiratory distress is not asthma, but laryngotracheal irritation/spasm/suffocation.
基金supported by funding from King Abdullah University of Science and Technology(KAUST),BAS/1/1614-01-01,KCR/1/2081-01-01 and GEN/1/6607-01-01,and the KAUST-KFUPM Special Initiative,REP/1/2878-01-01the financial support from the King Abdulaziz City for Science and Technology(KACST),Grant no.KACST TIC R2-FP-008.
文摘Optical wireless communication(OWC)using the ultra-broad spectrum of the visible-to-ultraviolet(UV)wavelength region remains a vital field of research for mitigating the saturated bandwidth of radio-frequency(RF)communication.However,the lack of an efficient UV photodetection methodology hinders the development of UV-based communication.The key technological impediment is related to the low UV-photon absorption in existing silicon photodetectors,which offer low-cost and mature platforms.To address this technology gap,we report a hybrid Sibased photodetection scheme by incorporating CsPbBr_(3) perovskite nanocrystals(NCs)with a high photoluminescence quantum yield(PLQY)and a fast photoluminescence(PL)decay time as a UV-to-visible colourconverting layer for high-speed solar-blind UV communication.The facile formation of drop-cast CsPbBr_(3) perovskite NCs leads to a high PLQY of up to ~73% and strong absorption in the UV region.With the addition of the NC layer,a nearly threefold improvement in the responsivity and an increase of ~25% in the external quantum efficiency(EQE)of the solar-blind region compared to a commercial silicon-based photodetector were observed.Moreover,timeresolved photoluminescence measurements demonstrated a decay time of 4.5 ns under a 372-nm UV excitation source,thus elucidating the potential of this layer as a fast colour-converting layer.A high data rate of up to 34 Mbps in solar-blind communication was achieved using the hybrid CsPbBr_(3)-silicon photodetection scheme in conjunction with a 278-nm UVC light-emitting diode(LED).These findings demonstrate the feasibility of an integrated high-speed photoreceiver design of a composition-tuneable perovskite-based phosphor and a low-cost silicon-based photodetector for UV communication.
基金the Ministry of Higher Education,Malaysia(MOHE)for the financial supports received under University Grant(08H05)and Fundamental Research Grant Scheme(4F872)Universiti Teknologi Malaysia for the GUP grant No.17H65the support to the main author,Wong Syie Luing,in the form of Post-Doctoral Fellowship Scheme for the project"Catalytic Cracking of Low Density Polyethylene Waste to Liquid Fuels in Fixed Bed Reactor"
文摘Adsorption is an important process in wastewater treatment,and conversion of waste materials to adsorbent offers a solution to high material cost related to the use of commercial activated carbon.This study investigated the adsorption behaviour of Reactive Black 5（RB5）and methylene blue（MB）onto activated carbon produced from textile sludge（TSAC）.The activated carbon was synthesized through chemical activation of precursor followed with carbonization at 650℃ under nitrogen flow.Effects of time（0–200 min）,pH（2–10）,temperature（25–60℃）,initial dye concentration（0–200 mg·L^-1）,and adsorbent dosage（0.01–0.15 g）on dye removal efficiency were investigated.Preliminary screening revealed that TSAC synthesized via H2SO4activation showed higher adsorption behaviour than TSAC activated by KCl and ZnCl2.The adsorption capacity of TSAC was found to be 11.98 mg·g^-1（RB5）and 13.27 mg·g^-1（MB）,and is dependent on adsorption time and initial dye concentration.The adsorption data for both dyes were well fitted to Freundlich isotherm model which explains the heterogeneous nature of TSAC surface.The dye adsorption obeyed pseudo-second order kinetic model,thus chemisorption was the controlling step.This study reveals potential of textile sludge in removal of dyes from aqueous solution,and further studies are required to establish the applicability of the synthesized adsorbent for the treatment of waste water containing toxic dyes from textile industry.
文摘Mobile ad-hoc networks （MANETs） and wireless sensor networks （WSNs） have gained remarkable apprecia- tion and technological development over the last few years. Despite ease of deployment, tremendous applications and significant advantages, security has always been a challeng- ing issue due to the nature of environments in which nodes operate. Nodes＇ physical capture, malicious or selfish behav- ior cannot be detected by traditional security schemes. Trust and reputation based approaches have gained global recog- nition in providing additional means of security for decision making in sensor and ad-hoc networks. This paper provides an extensive literature review of trust and reputation based models both in sensor and ad-hoc networks. Based on the mechanism of trust establishment, we categorize the state- of-the-art into two groups namely node-centric trust mod- els and system-centric trust models. Based on trust evidence, initialization, computation, propagation and weight assign- ments, we evaluate the efficacy of the existing schemes. Fi- nally, we conclude our discussion with identification of some unresolved issues in pursuit of trust and reputation manage- ment.
