Aim: To study the association between seminal oxidative stress and human sperm acrosin activity. Methods: It is a prospective study consisting of 30 infertile men and 12 fertile normozoospermic volunteers. A full hist...Aim: To study the association between seminal oxidative stress and human sperm acrosin activity. Methods: It is a prospective study consisting of 30 infertile men and 12 fertile normozoospermic volunteers. A full history, clinical examination and scrotal ultrasound were done to exclude other related factors such as smoking and varicocele. Presence of white blood cells (WBCs) in semen samples was evaluated by peroxidase staining. Lipid peroxidation in spermatozoa was induced after incubating with ferrous sulphate (4 mmol/L) and sodium ascorbate (20 mmol/L). Induced peroxidation of spermatozoa was assessed by determining the production of thiobarbituric acid reactive substances (TBARS). Acrosin activity was measured using the gelatinolysis technique. The halo diameters around the sperm heads and the percentages of spermatozoa showing halo formation were evaluated. An acrosin activity index was calculated by multiplying the halo diameter by the halo formation rate. Results: A significant difference was observed in acrosin activity parameters and TBARS levels between samples with WBCs (>1×106/mL of ejaculate) and those without. This difference was also noted between the normozoospermic and the oligoasthenoteratozoospermic semen samples. The TBARS production by spermatozoa had a significant negative correlation with the acrosin activity index (r = -0.89, P <0.001). Conclusion: The presence of oxidative stress in an individual with leukocytospermia and/or abnormal semen parameters is associated with impaired sperm function as measured by its acrosin activity.展开更多
Objective:To explore the in vivo anticancer,anti-angiogenesis and immunomodulatory efficacies of the bioactive polysaccharide isolated from cold aqueous extract of Jania rubens(JCEM) and Pterocladia capillacea(PCEM) a...Objective:To explore the in vivo anticancer,anti-angiogenesis and immunomodulatory efficacies of the bioactive polysaccharide isolated from cold aqueous extract of Jania rubens(JCEM) and Pterocladia capillacea(PCEM) as well as hot aqueous extract of Enteromorpha intestinalis(EHEM) against hepatocellular carcinoma rat model(HCC) and to study their chemical composition.Methods:The sugars and amino acids composition of the bioactive polysaccharides of JCEM,PCEM and EHEM were determined using gas liquid chromatography and amino acid analyzer,respectively.These polysaccharide extracts(20 mg/kg b.wt.for 5 weeks) were assessed on hepatocarcinogenesis in rats and α-fetoprotein(AFP),carcinoembryonic antigen(CEA),glypican-3(GPC-3),hepatocyte growth factor(HGF) and vascular endothelial growth factor(VEGF) and Ig G levels were evaluated.Results:The GLC analysis of JCEM,PCEM and EHEM polysaccharide revealed the presence of 10,9 and10 sugars,in addition the amino acid analyser enable identification of 16,15 and 15 amino acids,respectively.These polysaccharide extracts of JCEM,PCEM and EHEM produced significant decrease in serum AFP,CEA,GPC-3,HGF and VEGF compared with untreated HCC group.JCEM,PCEM and EHEM had an immunostimulatory responses by increasing the IgG levels as compared by naive value(1.23,1.53 and 1.17 folds),respectively.The bioactive polysaccharides in HCC induced rats improved the humoral immune response.The photomicrographs of liver tissue sections of the groups of HCC treated with polysaccharide extracts of Jania rubens and Enteromorpha intestinalis showed intact histological structure.Moreover,fractions HE1,HE4,HE7 obtained from polysaccharide of EHEM showed moderate cytotoxic activity against Hep G2 in vitro with IC_(50) 73.1,42.6,76.2 μg/mL.However,fractions of PCEM and JCEM show no or weak cytotoxicity against Hep G2 in vitro where the cytotoxic activity of their crude polysaccharide extract proved synergetic effect.Conclusions:The pronounced antitumor activity of sulphated polysaccharide-protein complex展开更多
The interaction of relativistically intense lasers with opaque targets represents a highly non-linear,multi-dimensional parameter space.This limits the utility of sequential 1D scanning of experimental parameters for ...The interaction of relativistically intense lasers with opaque targets represents a highly non-linear,multi-dimensional parameter space.This limits the utility of sequential 1D scanning of experimental parameters for the optimization of secondary radiation,although to-date this has been the accepted methodology due to low data acquisition rates.High repetition-rate(HRR)lasers augmented by machine learning present a valuable opportunity for efficient source optimization.Here,an automated,HRR-compatible system produced high-fidelity parameter scans,revealing the influence of laser intensity on target pre-heating and proton generation.A closed-loop Bayesian optimization of maximum proton energy,through control of the laser wavefront and target position,produced proton beams with equivalent maximum energy to manually optimized laser pulses but using only 60%of the laser energy.This demonstration of automated optimization of laser-driven proton beams is a crucial step towards deeper physical insight and the construction of future radiation sources.展开更多
We present the development and characterization of a high-stability,multi-material,multi-thickness tape-drive target for laser-driven acceleration at repetition rates of up to 100 Hz.The tape surface position was meas...We present the development and characterization of a high-stability,multi-material,multi-thickness tape-drive target for laser-driven acceleration at repetition rates of up to 100 Hz.The tape surface position was measured to be stable on the sub-micrometre scale,compatible with the high-numerical aperture focusing geometries required to achieve relativistic intensity interactions with the pulse energy available in current multi-Hz and near-future higher repetition-rate lasers(>kHz).Long-term drift was characterized at 100 Hz demonstrating suitability for operation over extended periods.The target was continuously operated at up to 5 Hz in a recent experiment for 70,000 shots without intervention by the experimental team,with the exception of tape replacement,producing the largest data-set of relativistically intense laser–solid foil measurements to date.This tape drive provides robust targetry for the generation and study of high-repetitionrate ion beams using next-generation high-power laser systems,also enabling wider applications of laser-driven proton sources.展开更多
Traditional security systems are exposed to many various attacks,which represents a major challenge for the spread of the Internet in the future.Innovative techniques have been suggested for detecting attacks using ma...Traditional security systems are exposed to many various attacks,which represents a major challenge for the spread of the Internet in the future.Innovative techniques have been suggested for detecting attacks using machine learning and deep learning.The significant advantage of deep learning is that it is highly efficient,but it needs a large training time with a lot of data.Therefore,in this paper,we present a new feature reduction strategy based on Distributed Cumulative Histograms(DCH)to distinguish between dataset features to locate the most effective features.Cumulative histograms assess the dataset instance patterns of the applied features to identify the most effective attributes that can significantly impact the classification results.Three different models for detecting attacks using Convolutional Neural Network(CNN)and Long Short-Term Memory Network(LSTM)are also proposed.The accuracy test of attack detection using the hybrid model was 98.96%on the UNSW-NP15 dataset.The proposed model is compared with wrapper-based and filter-based Feature Selection(FS)models.The proposed model reduced classification time and increased detection accuracy.展开更多
Besides（-）-epicatechin,epicatechin-（4β-8 ）-epicatechin（procyanidin B2）,epicatechin-（4β-6 ）-epicatechin （procyanidin B5）,epicatechin-（4β-8,2β-O-7）-epicatechin（proanthocyanidin A2） and epicatechin- （4...Besides（-）-epicatechin,epicatechin-（4β-8 ）-epicatechin（procyanidin B2）,epicatechin-（4β-6 ）-epicatechin （procyanidin B5）,epicatechin-（4β-8,2β-O-7）-epicatechin（proanthocyanidin A2） and epicatechin- （4β-8）-epicatechin-（4β-8）-epicatechin（procyanidin C1）,which were isolated before from Adansonia digitata, in this work an A-type proanthocyanidin trimer,i.e.epicatechin-（4β-8）-epicatechin-（4β-8,2β-0-7）- epicatechin,tetrameric procyanidin D1,i.e.epicatechin-（4β-8）-epicatechin-（4β-8）-epicatechin-（4β-8）- epicatechin and a polymeric compound were isolated from the pericarp（fruit wall） of the fruits for the first time from this plant.The antioxidant activity of different fractions and pure compounds was experimentally evaluated in the DPPH<sup>-</sup> assay.The ethyl acetate fraction,and most of the isolated compounds displayed a high activity(IC<sub>50</sub> 2.40-9.60μg/ml) compared with the reference antioxidant Trolox(IC<sub>50</sub> 12.18μg/ml) as a standard.展开更多
Accurately known energy level structure of the A＇∑u＋b3 IIu complex of states from a recent global de-perturbation of these states has enabled additional assignments of 140 perturbation facilitated infrared-infrared...Accurately known energy level structure of the A＇∑u＋b3 IIu complex of states from a recent global de-perturbation of these states has enabled additional assignments of 140 perturbation facilitated infrared-infrared double resonance （PFIIDR） transitions to the 2^3△1g state from collisionally populated intermediate 1 ＋ A Eu levels. Together with the 221 previously observed 2^3△1g←A1∑u＋←X1∑g＋ Eu X Eg double resonance lines [J. Chem. Phys. 128, 204313 （2008）], molecular constants and the Rydberg-Klein-Rees potential energy curve of the 23△1g state have been recalculated （excluding 54 perturbed levels）. The centrifugal distortion constant has been determined and agrees well with the value calculated based on standard empirical formulas. The hyperfine structure of the 23△1g state, which has not resolved in our sub-Doppler excitation spectra of the 23△1g state, has been interpreted with a preliminary simulation.展开更多
The ultrafast charge dynamics following the interaction of an ultra-intense laser pulse with a foil target leads to the launch of an ultra-short, intense electromagnetic(EM) pulse along a wire connected to the target....The ultrafast charge dynamics following the interaction of an ultra-intense laser pulse with a foil target leads to the launch of an ultra-short, intense electromagnetic(EM) pulse along a wire connected to the target. Due to the strong electric field(of the order of GV m^(-1)) associated to such laser-driven EM pulses, these can be exploited in a travelling-wave helical geometry for controlling and optimizing the parameters of laser accelerated proton beams. The propagation of the EM pulse along a helical path was studied by employing a proton probing technique. The pulse-carrying coil was probed along two orthogonal directions, transverse and parallel to the coil axis. The temporal profile of the pulse obtained from the transverse probing of the coil is in agreement with the previous measurements obtained in a planar geometry. The data obtained from the longitudinal probing of the coil shows a clear evidence of an energy dependent reduction of the proton beam divergence, which underpins the mechanism behind selective guiding of laser-driven ions by the helical coil targets.展开更多
Introduction: Severe acute respiratory syndrome coronavirus2 (SARS-CoV-2) represents a major health problem worldwide. Thus, early detection and appropriate management of the virus will influence the outcome of the di...Introduction: Severe acute respiratory syndrome coronavirus2 (SARS-CoV-2) represents a major health problem worldwide. Thus, early detection and appropriate management of the virus will influence the outcome of the disease. This study aimed to investigate the epidemiological characteristics and survival outcomes of patients with COVID-19 infection in Kassala, Eastern Sudan. Methods: A cross-sectional hospital-study was conducted among patients visiting Kassala teaching hospital with suspicion of COVID-19 infection. A structured questionnaire was used to gather clinical and socio-demo- graphic information from COVID-19 patients. Nasopharyngeal specimens and blood samples were collected and tested to confirm the diagnosis of COVID-19 infection using RT-PCR. Results: A total of 371 patients were enrolled in the study from September 2020 to January 2021, with mean age ± SD was 42.9 ± 19.9. The prevalence of COVID-19 infection was estimated at 61.7%. The majority were males 159 (69.4%), of university-level education, 96 (49.7%), and urban residents, 175 (9.7%). The most common symptoms were fever 215 (93.9%), cough 188 (82.1%), headache 179 (78.2%), and shortness of breath 154 (67.2%). Overall all mortality was reported as 16%. Older age group with the age ≥ 70, P P = 0.020, diabetes mellitus P = 0.029 were significantly associated with high case fatality. Conclusion: This study demonstrated that older age, male gender, laboratory tests (leukocytosis, lymphopenia, low Hemoglobin and high CRP) and various comorbid conditions significantly increase the disease severity and mortality. Therefore, attention should be paid to preventive measures to reduce the considerable impacts of the disease.展开更多
Information security has emerged as a key problem in encryption because of the rapid evolution of the internet and networks.Thus,the progress of image encryption techniques is becoming an increasingly serious issue an...Information security has emerged as a key problem in encryption because of the rapid evolution of the internet and networks.Thus,the progress of image encryption techniques is becoming an increasingly serious issue and considerable problem.Small space of the key,encryption-based low confidentiality,low key sensitivity,and easily exploitable existing image encryption techniques integrating chaotic system and DNA computing are purposing the main problems to propose a new encryption technique in this study.In our proposed scheme,a three-dimensional Chen’s map and a one-dimensional Logistic map are employed to construct a double-layer image encryption scheme.In the confusion stage,different scrambling operations related to the original plain image pixels are designed using Chen’s map.A stream pixel scrambling operation related to the plain image is constructed.Then,a block scrambling-based image encryption-related stream pixel scrambled image is designed.In the diffusion stage,two rounds of pixel diffusion are generated related to the confusing image for intra-image diffusion.Chen’s map,logistic map,and DNA computing are employed to construct diffusion operations.A reverse complementary rule is applied to obtain a new form of DNA.A Chen’s map is used to produce a pseudorandom DNA sequence,and then another DNA form is constructed from a reverse pseudorandom DNA sequence.Finally,the XOR operation is performed multiple times to obtain the encrypted image.According to the simulation of experiments and security analysis,this approach extends the key space,has great sensitivity,and is able to withstand various typical attacks.An adequate encryption effect is achieved by the proposed algorithm,which can simultaneously decrease the correlation between adjacent pixels by making it near zero,also the information entropy is increased.The number of pixels changing rate(NPCR)and the unified average change intensity(UACI)both are very near to optimal values.展开更多
<span style="font-family:Verdana;">Osseous metaplasia of the breast is considered to be one of the rare breast conditions. It is characterized by the presence of normal bone tissue within the breast. W...<span style="font-family:Verdana;">Osseous metaplasia of the breast is considered to be one of the rare breast conditions. It is characterized by the presence of normal bone tissue within the breast. We report a case of benign osseous metaplasia in a 58-year-old woman presenting with mastalgia and mass in the right breast. A lumpectomy was performed. On the pathological examination, the mass was composed completely of benign bone trabeculae with no epithelial component which was confirmed by negativity of immunohistochemistry.</span>展开更多
Introduction: Hepatitis C virus (HCV) genotype 4 is the most prevalent in Egypt. Vis-ceral adiposity index (VAI) and (TyG) index are newly developed indices for assess-ment of metabolic syndrome (MS) and insulin resis...Introduction: Hepatitis C virus (HCV) genotype 4 is the most prevalent in Egypt. Vis-ceral adiposity index (VAI) and (TyG) index are newly developed indices for assess-ment of metabolic syndrome (MS) and insulin resistance (IR). We aimed at comparing their levels in HCV-patients with healthy controls and validate their use for prediction of hepatic histopathological changes. Patient and Methods: 78 chronic HCV-infected patients proven by PCR, viral genotyping and hepatic histopathology, and 67 healthy controls were enrolled. Presence of MS, Homeostasis Model Assessment for IR esti-mation (HOMA-IR), TyG index, and VAI were assessed. Results: HOMA-IR, TyG and frequency of MS were significantly higher in patients’ group (p p p = 0.002). Conclusion: HCV genotype 4 is significantly associated with MS and increased values of HOMA IR and TyG index. TyG index and VAI are valuable simple indices that could predict the histopathological changes in Egyptian CHC pa-tients.展开更多
This study investigates a strong magnetic field acting over an elastic rotator semiconductor medium.The Thomson effect due to the magnetic field during the photothermal transport process is studied,and the thermoelect...This study investigates a strong magnetic field acting over an elastic rotator semiconductor medium.The Thomson effect due to the magnetic field during the photothermal transport process is studied,and the thermoelectricity theory is used to explain the behavior of waves in the homogenous and isotropic medium under the effect of variable thermal conductivity.The variable thermal conductivity is considered as a linear function of the temperature.The two-dimensional deformation equations are used to describe the overlaps among plasma,electrical,thermal,and magneto-elastic waves.The charge density of inertia-particles is considered as a function of time for studying the induced electric current.The normal mode analysis is used to obtain the exact solutions of the physical field distributions as part of this phenomenon.To obtain the complete solutions of the physical field quantities,the certain mechanical loads,electromagnetic effects,thermal effects,and plasma recombination process are applied herein.The results of the physical distributions are graphically depicted and discussed in consideration of the internal heat source,rotation,and Peltier coefficient.展开更多
Site selection for location of a hospital is one of the crucial policy-related decisions taken by the government. In upper Egypt, the cities suffer from a shortage and bad distribution of hospital site. The selection ...Site selection for location of a hospital is one of the crucial policy-related decisions taken by the government. In upper Egypt, the cities suffer from a shortage and bad distribution of hospital site. The selection of the appropriate hospital site requires consideration of multiple alternative solutions and evaluation factor. We develop a Multi-Criteria Decision Support System (MCDSS) process that combines Geographical Information System (GIS) analysis with Analytical Hierarchy Process (AHP) and use this process to determine the optimum site for a new hospital in the Aswan urban area. Based on actual conditions Aswan city, we used three main factors and seven sub-factors. The main factors are urban, environmental and economic factors. An application adopting AHP process was developed to calculate weights of every factor. Spatial analysis in GIS was used to overlay and generate factors maps and suitability evaluation map. All maps are classified from 1 (low suitable) to 5 (high suitable) using spatial information technologies. The candidate sites are divided by best, good and unsuitable hospital areas. Best hospital site represents optimal sites;good hospital site can be used as back-up candidate sites. The study was found that best area (S3) is about 30%, and most of these are located in the south part of the study area;good area (S2) is about 58%, and most of these are located in the central part of the study area;unsuitable area (S1) is about 12%, and most of these are located in the Eastern and Western parts of the study area. Finally, the study ends with an assessment of proposed sites.展开更多
We demonstrate a femtosecond mode-locked erbium-doped fiber laser（EDFL） using a nickel oxide（Ni O） as a saturable absorber（SA）. Ni O nanoparticles are hosted into polyethylene oxide film and attached to fiber fe...We demonstrate a femtosecond mode-locked erbium-doped fiber laser（EDFL） using a nickel oxide（Ni O） as a saturable absorber（SA）. Ni O nanoparticles are hosted into polyethylene oxide film and attached to fiber ferrule in the laser cavity. The Ni O-SA shows a 39% modulation depth with a 0.04 MW∕cm^2 saturation intensity. Our ring laser cavity based on erbium-doped active fiber with managed intracavity dispersion has the ability to generate ultrashort pulses with a full width at half-maximum（FWHM） of around 2.85 nm centered at 1561.8 nm.The pulses repeat at a frequency of 0.96 MHz and duration of 950 fs.展开更多
We demonstrate a Q-switched ytterbium-doped fiber laser （YDFL） using a newly developed multi-layer black phosphorous （BP） saturable absorber （SA）. The BP SA is prepared by mechanically exfoliating a BP crystal a...We demonstrate a Q-switched ytterbium-doped fiber laser （YDFL） using a newly developed multi-layer black phosphorous （BP） saturable absorber （SA）. The BP SA is prepared by mechanically exfoliating a BP crystal and sticking the acquired BP flakes onto a scotch tape. A small piece of the tape is then placed between two ferrules and incorporated in a YDFL cavity to achieve a stable Q-switched operation in a 1.0 μm region. The laser has a pump threshold of 55.1 mW, a pulse repetition rate that is tunable from 8.2 to 32.9 kHz, and the narrowest pulse width of 10.8 μs. The highest pulse energy of 328 nJ is achieved at the pump power of 97.6 mW. Our results show that multi-layer BP is a promising SA for Q-switching laser operation.展开更多
AIM： To assess the frequency and associated risk fac- tors of diabetic retinopathy among Sudanese individuals with diabetes attending Makka Eye complex in Khartoum, Sudan. METHODS： The cross sectional hospital base...AIM： To assess the frequency and associated risk fac- tors of diabetic retinopathy among Sudanese individuals with diabetes attending Makka Eye complex in Khartoum, Sudan. METHODS： The cross sectional hospital based study recruited 316 individuals with diabetes from Makkah Eye Complex Retina Clinic. Standard questionnaire was used to collect demographic data, medical history and life style characteristics. Blood samples were taken to measure HbAlc and lipid profile. Fundus and slit lamp examination were performed for screening of diabetic retinopathy. RESULTS： Among 316 participants, 187 （59.2%） were males and 129 （40.8%） were females. The mean age of participants was 58.7＋_10.5y. The overall frequency of retinopathy was 261 （82.6%）. The percentages of the total participants with proliferative diabetic retinopathy （PDR） were 126 （39.9%） and non-proliferative diabetic retinopathy （NPDR） were 135 （42.7%）. importantly, duration of diabetes mellitus （DM） （72.2% of more than 10y）, being on oral hypoglycaemic drugs （versus insulin）, and hypertension were all significant risk factors for diabetic retinopathy （P=0.00, 0.01 and 0.00 respectively）. Complications ofdiabetes like diabetic foot （17.7%）, history of amputation （6.7%） and clinically significant macular edema （CSME） （47.4%） of the eyes were all significant risk factors （P〈0.05）. Logistic regression analysis showed that duration of diabetes, hypertension and CSME were found to be absolute risk factors （P=-0.007, 0.003 and 0,000 respectively）. Duration of DM of more than 10y have more than double risk （OR--2.8）, while having hypertension triples the risk of retinopathy （OR=3.1）. CONCLUSION： High rates of diabetic retinopathy are noted among individuals with diabetes attending Makkah Eye hospital in capital Khartoum. Urgent strategies are needed to monitor and treat hypertension and optimize diabetes control in individuals with diabetes. More investment in diabetes services is展开更多
文摘Aim: To study the association between seminal oxidative stress and human sperm acrosin activity. Methods: It is a prospective study consisting of 30 infertile men and 12 fertile normozoospermic volunteers. A full history, clinical examination and scrotal ultrasound were done to exclude other related factors such as smoking and varicocele. Presence of white blood cells (WBCs) in semen samples was evaluated by peroxidase staining. Lipid peroxidation in spermatozoa was induced after incubating with ferrous sulphate (4 mmol/L) and sodium ascorbate (20 mmol/L). Induced peroxidation of spermatozoa was assessed by determining the production of thiobarbituric acid reactive substances (TBARS). Acrosin activity was measured using the gelatinolysis technique. The halo diameters around the sperm heads and the percentages of spermatozoa showing halo formation were evaluated. An acrosin activity index was calculated by multiplying the halo diameter by the halo formation rate. Results: A significant difference was observed in acrosin activity parameters and TBARS levels between samples with WBCs (>1×106/mL of ejaculate) and those without. This difference was also noted between the normozoospermic and the oligoasthenoteratozoospermic semen samples. The TBARS production by spermatozoa had a significant negative correlation with the acrosin activity index (r = -0.89, P <0.001). Conclusion: The presence of oxidative stress in an individual with leukocytospermia and/or abnormal semen parameters is associated with impaired sperm function as measured by its acrosin activity.
基金the National Research Centre for the financial support with Grant No.9080104
文摘Objective:To explore the in vivo anticancer,anti-angiogenesis and immunomodulatory efficacies of the bioactive polysaccharide isolated from cold aqueous extract of Jania rubens(JCEM) and Pterocladia capillacea(PCEM) as well as hot aqueous extract of Enteromorpha intestinalis(EHEM) against hepatocellular carcinoma rat model(HCC) and to study their chemical composition.Methods:The sugars and amino acids composition of the bioactive polysaccharides of JCEM,PCEM and EHEM were determined using gas liquid chromatography and amino acid analyzer,respectively.These polysaccharide extracts(20 mg/kg b.wt.for 5 weeks) were assessed on hepatocarcinogenesis in rats and α-fetoprotein(AFP),carcinoembryonic antigen(CEA),glypican-3(GPC-3),hepatocyte growth factor(HGF) and vascular endothelial growth factor(VEGF) and Ig G levels were evaluated.Results:The GLC analysis of JCEM,PCEM and EHEM polysaccharide revealed the presence of 10,9 and10 sugars,in addition the amino acid analyser enable identification of 16,15 and 15 amino acids,respectively.These polysaccharide extracts of JCEM,PCEM and EHEM produced significant decrease in serum AFP,CEA,GPC-3,HGF and VEGF compared with untreated HCC group.JCEM,PCEM and EHEM had an immunostimulatory responses by increasing the IgG levels as compared by naive value(1.23,1.53 and 1.17 folds),respectively.The bioactive polysaccharides in HCC induced rats improved the humoral immune response.The photomicrographs of liver tissue sections of the groups of HCC treated with polysaccharide extracts of Jania rubens and Enteromorpha intestinalis showed intact histological structure.Moreover,fractions HE1,HE4,HE7 obtained from polysaccharide of EHEM showed moderate cytotoxic activity against Hep G2 in vitro with IC_(50) 73.1,42.6,76.2 μg/mL.However,fractions of PCEM and JCEM show no or weak cytotoxicity against Hep G2 in vitro where the cytotoxic activity of their crude polysaccharide extract proved synergetic effect.Conclusions:The pronounced antitumor activity of sulphated polysaccharide-protein complex
基金support from the UK STFC grants ST/V001639/1 with the XFEL Physical Sciences Hub and ST/P002021/1the UK EPSRC grants EP/V049577/1 and EP/R006202/1+5 种基金as well as the U.S.DOE Office of Science,Fusion Energy Sciences under FWP No.100182in part by the National Science Foundation under Grant No.1632708 and Award No.PHY–1903414M.J.V.S.acknowledges support from the Royal Society URFR1221874support from the DOE NNSA SSGF program under DE-NA0003960support from the U.S.DOE grant DESC0016804support from the project‘Advanced research using high-intensity laser-produced photons and particles’(CZ.02.1.01/0.0/0.0/16_019/0000789)from the European Regional Development Fund(ADONIS)。
文摘The interaction of relativistically intense lasers with opaque targets represents a highly non-linear,multi-dimensional parameter space.This limits the utility of sequential 1D scanning of experimental parameters for the optimization of secondary radiation,although to-date this has been the accepted methodology due to low data acquisition rates.High repetition-rate(HRR)lasers augmented by machine learning present a valuable opportunity for efficient source optimization.Here,an automated,HRR-compatible system produced high-fidelity parameter scans,revealing the influence of laser intensity on target pre-heating and proton generation.A closed-loop Bayesian optimization of maximum proton energy,through control of the laser wavefront and target position,produced proton beams with equivalent maximum energy to manually optimized laser pulses but using only 60%of the laser energy.This demonstration of automated optimization of laser-driven proton beams is a crucial step towards deeper physical insight and the construction of future radiation sources.
基金Special thanks go to the staff at the Central Laser Facility who provided laser operational support,mechanical and electrical support and computational and administrative support throughout the experiment.We acknowledge funding from UK STFC,Grant Nos.ST/P002021/1 and ST/V001639/1U.S.DOE Office of Science,Fusion Energy Sciences under FWP No.100182+2 种基金in part by the National Science Foundation under Grant No.1632708G.D.G.acknowledges support from the DOE NNSA SSGF program under DE-NA0003960This work has been partially supported by the project Advanced Research Using High-intensity Laser-produced Photons and Particles(CZ.02.1.01/0.0/0.0/16_019/0000789)from the European Regional Development Fund(ADONIS).
文摘We present the development and characterization of a high-stability,multi-material,multi-thickness tape-drive target for laser-driven acceleration at repetition rates of up to 100 Hz.The tape surface position was measured to be stable on the sub-micrometre scale,compatible with the high-numerical aperture focusing geometries required to achieve relativistic intensity interactions with the pulse energy available in current multi-Hz and near-future higher repetition-rate lasers(>kHz).Long-term drift was characterized at 100 Hz demonstrating suitability for operation over extended periods.The target was continuously operated at up to 5 Hz in a recent experiment for 70,000 shots without intervention by the experimental team,with the exception of tape replacement,producing the largest data-set of relativistically intense laser–solid foil measurements to date.This tape drive provides robust targetry for the generation and study of high-repetitionrate ion beams using next-generation high-power laser systems,also enabling wider applications of laser-driven proton sources.
文摘Traditional security systems are exposed to many various attacks,which represents a major challenge for the spread of the Internet in the future.Innovative techniques have been suggested for detecting attacks using machine learning and deep learning.The significant advantage of deep learning is that it is highly efficient,but it needs a large training time with a lot of data.Therefore,in this paper,we present a new feature reduction strategy based on Distributed Cumulative Histograms(DCH)to distinguish between dataset features to locate the most effective features.Cumulative histograms assess the dataset instance patterns of the applied features to identify the most effective attributes that can significantly impact the classification results.Three different models for detecting attacks using Convolutional Neural Network(CNN)and Long Short-Term Memory Network(LSTM)are also proposed.The accuracy test of attack detection using the hybrid model was 98.96%on the UNSW-NP15 dataset.The proposed model is compared with wrapper-based and filter-based Feature Selection(FS)models.The proposed model reduced classification time and increased detection accuracy.
文摘Besides（-）-epicatechin,epicatechin-（4β-8 ）-epicatechin（procyanidin B2）,epicatechin-（4β-6 ）-epicatechin （procyanidin B5）,epicatechin-（4β-8,2β-O-7）-epicatechin（proanthocyanidin A2） and epicatechin- （4β-8）-epicatechin-（4β-8）-epicatechin（procyanidin C1）,which were isolated before from Adansonia digitata, in this work an A-type proanthocyanidin trimer,i.e.epicatechin-（4β-8）-epicatechin-（4β-8,2β-0-7）- epicatechin,tetrameric procyanidin D1,i.e.epicatechin-（4β-8）-epicatechin-（4β-8）-epicatechin-（4β-8）- epicatechin and a polymeric compound were isolated from the pericarp（fruit wall） of the fruits for the first time from this plant.The antioxidant activity of different fractions and pure compounds was experimentally evaluated in the DPPH<sup>-</sup> assay.The ethyl acetate fraction,and most of the isolated compounds displayed a high activity(IC<sub>50</sub> 2.40-9.60μg/ml) compared with the reference antioxidant Trolox(IC<sub>50</sub> 12.18μg/ml) as a standard.
文摘Accurately known energy level structure of the A＇∑u＋b3 IIu complex of states from a recent global de-perturbation of these states has enabled additional assignments of 140 perturbation facilitated infrared-infrared double resonance （PFIIDR） transitions to the 2^3△1g state from collisionally populated intermediate 1 ＋ A Eu levels. Together with the 221 previously observed 2^3△1g←A1∑u＋←X1∑g＋ Eu X Eg double resonance lines [J. Chem. Phys. 128, 204313 （2008）], molecular constants and the Rydberg-Klein-Rees potential energy curve of the 23△1g state have been recalculated （excluding 54 perturbed levels）. The centrifugal distortion constant has been determined and agrees well with the value calculated based on standard empirical formulas. The hyperfine structure of the 23△1g state, which has not resolved in our sub-Doppler excitation spectra of the 23△1g state, has been interpreted with a preliminary simulation.
基金funding from EPSRC,[EP/J002550/1-Career Acceleration Fellowship held by S.K.,EP/L002221/1,EP/K022415/1,and EP/I029206/1],SBFTR18 and GRK1203,EC-GA284464 and Invest Northern Ireland(POC-329)
文摘The ultrafast charge dynamics following the interaction of an ultra-intense laser pulse with a foil target leads to the launch of an ultra-short, intense electromagnetic(EM) pulse along a wire connected to the target. Due to the strong electric field(of the order of GV m^(-1)) associated to such laser-driven EM pulses, these can be exploited in a travelling-wave helical geometry for controlling and optimizing the parameters of laser accelerated proton beams. The propagation of the EM pulse along a helical path was studied by employing a proton probing technique. The pulse-carrying coil was probed along two orthogonal directions, transverse and parallel to the coil axis. The temporal profile of the pulse obtained from the transverse probing of the coil is in agreement with the previous measurements obtained in a planar geometry. The data obtained from the longitudinal probing of the coil shows a clear evidence of an energy dependent reduction of the proton beam divergence, which underpins the mechanism behind selective guiding of laser-driven ions by the helical coil targets.
文摘Introduction: Severe acute respiratory syndrome coronavirus2 (SARS-CoV-2) represents a major health problem worldwide. Thus, early detection and appropriate management of the virus will influence the outcome of the disease. This study aimed to investigate the epidemiological characteristics and survival outcomes of patients with COVID-19 infection in Kassala, Eastern Sudan. Methods: A cross-sectional hospital-study was conducted among patients visiting Kassala teaching hospital with suspicion of COVID-19 infection. A structured questionnaire was used to gather clinical and socio-demo- graphic information from COVID-19 patients. Nasopharyngeal specimens and blood samples were collected and tested to confirm the diagnosis of COVID-19 infection using RT-PCR. Results: A total of 371 patients were enrolled in the study from September 2020 to January 2021, with mean age ± SD was 42.9 ± 19.9. The prevalence of COVID-19 infection was estimated at 61.7%. The majority were males 159 (69.4%), of university-level education, 96 (49.7%), and urban residents, 175 (9.7%). The most common symptoms were fever 215 (93.9%), cough 188 (82.1%), headache 179 (78.2%), and shortness of breath 154 (67.2%). Overall all mortality was reported as 16%. Older age group with the age ≥ 70, P P = 0.020, diabetes mellitus P = 0.029 were significantly associated with high case fatality. Conclusion: This study demonstrated that older age, male gender, laboratory tests (leukocytosis, lymphopenia, low Hemoglobin and high CRP) and various comorbid conditions significantly increase the disease severity and mortality. Therefore, attention should be paid to preventive measures to reduce the considerable impacts of the disease.
基金Deanship for Research&Innovation,Ministry of Education in Saudi Arabia for funding this research work through the Project Number:IFP22UQU4400257DSR031.
文摘Information security has emerged as a key problem in encryption because of the rapid evolution of the internet and networks.Thus,the progress of image encryption techniques is becoming an increasingly serious issue and considerable problem.Small space of the key,encryption-based low confidentiality,low key sensitivity,and easily exploitable existing image encryption techniques integrating chaotic system and DNA computing are purposing the main problems to propose a new encryption technique in this study.In our proposed scheme,a three-dimensional Chen’s map and a one-dimensional Logistic map are employed to construct a double-layer image encryption scheme.In the confusion stage,different scrambling operations related to the original plain image pixels are designed using Chen’s map.A stream pixel scrambling operation related to the plain image is constructed.Then,a block scrambling-based image encryption-related stream pixel scrambled image is designed.In the diffusion stage,two rounds of pixel diffusion are generated related to the confusing image for intra-image diffusion.Chen’s map,logistic map,and DNA computing are employed to construct diffusion operations.A reverse complementary rule is applied to obtain a new form of DNA.A Chen’s map is used to produce a pseudorandom DNA sequence,and then another DNA form is constructed from a reverse pseudorandom DNA sequence.Finally,the XOR operation is performed multiple times to obtain the encrypted image.According to the simulation of experiments and security analysis,this approach extends the key space,has great sensitivity,and is able to withstand various typical attacks.An adequate encryption effect is achieved by the proposed algorithm,which can simultaneously decrease the correlation between adjacent pixels by making it near zero,also the information entropy is increased.The number of pixels changing rate(NPCR)and the unified average change intensity(UACI)both are very near to optimal values.
文摘<span style="font-family:Verdana;">Osseous metaplasia of the breast is considered to be one of the rare breast conditions. It is characterized by the presence of normal bone tissue within the breast. We report a case of benign osseous metaplasia in a 58-year-old woman presenting with mastalgia and mass in the right breast. A lumpectomy was performed. On the pathological examination, the mass was composed completely of benign bone trabeculae with no epithelial component which was confirmed by negativity of immunohistochemistry.</span>
文摘Introduction: Hepatitis C virus (HCV) genotype 4 is the most prevalent in Egypt. Vis-ceral adiposity index (VAI) and (TyG) index are newly developed indices for assess-ment of metabolic syndrome (MS) and insulin resistance (IR). We aimed at comparing their levels in HCV-patients with healthy controls and validate their use for prediction of hepatic histopathological changes. Patient and Methods: 78 chronic HCV-infected patients proven by PCR, viral genotyping and hepatic histopathology, and 67 healthy controls were enrolled. Presence of MS, Homeostasis Model Assessment for IR esti-mation (HOMA-IR), TyG index, and VAI were assessed. Results: HOMA-IR, TyG and frequency of MS were significantly higher in patients’ group (p p p = 0.002). Conclusion: HCV genotype 4 is significantly associated with MS and increased values of HOMA IR and TyG index. TyG index and VAI are valuable simple indices that could predict the histopathological changes in Egyptian CHC pa-tients.
文摘This study investigates a strong magnetic field acting over an elastic rotator semiconductor medium.The Thomson effect due to the magnetic field during the photothermal transport process is studied,and the thermoelectricity theory is used to explain the behavior of waves in the homogenous and isotropic medium under the effect of variable thermal conductivity.The variable thermal conductivity is considered as a linear function of the temperature.The two-dimensional deformation equations are used to describe the overlaps among plasma,electrical,thermal,and magneto-elastic waves.The charge density of inertia-particles is considered as a function of time for studying the induced electric current.The normal mode analysis is used to obtain the exact solutions of the physical field distributions as part of this phenomenon.To obtain the complete solutions of the physical field quantities,the certain mechanical loads,electromagnetic effects,thermal effects,and plasma recombination process are applied herein.The results of the physical distributions are graphically depicted and discussed in consideration of the internal heat source,rotation,and Peltier coefficient.
文摘Site selection for location of a hospital is one of the crucial policy-related decisions taken by the government. In upper Egypt, the cities suffer from a shortage and bad distribution of hospital site. The selection of the appropriate hospital site requires consideration of multiple alternative solutions and evaluation factor. We develop a Multi-Criteria Decision Support System (MCDSS) process that combines Geographical Information System (GIS) analysis with Analytical Hierarchy Process (AHP) and use this process to determine the optimum site for a new hospital in the Aswan urban area. Based on actual conditions Aswan city, we used three main factors and seven sub-factors. The main factors are urban, environmental and economic factors. An application adopting AHP process was developed to calculate weights of every factor. Spatial analysis in GIS was used to overlay and generate factors maps and suitability evaluation map. All maps are classified from 1 (low suitable) to 5 (high suitable) using spatial information technologies. The candidate sites are divided by best, good and unsuitable hospital areas. Best hospital site represents optimal sites;good hospital site can be used as back-up candidate sites. The study was found that best area (S3) is about 30%, and most of these are located in the south part of the study area;good area (S2) is about 58%, and most of these are located in the central part of the study area;unsuitable area (S1) is about 12%, and most of these are located in the Eastern and Western parts of the study area. Finally, the study ends with an assessment of proposed sites.
文摘We demonstrate a femtosecond mode-locked erbium-doped fiber laser（EDFL） using a nickel oxide（Ni O） as a saturable absorber（SA）. Ni O nanoparticles are hosted into polyethylene oxide film and attached to fiber ferrule in the laser cavity. The Ni O-SA shows a 39% modulation depth with a 0.04 MW∕cm^2 saturation intensity. Our ring laser cavity based on erbium-doped active fiber with managed intracavity dispersion has the ability to generate ultrashort pulses with a full width at half-maximum（FWHM） of around 2.85 nm centered at 1561.8 nm.The pulses repeat at a frequency of 0.96 MHz and duration of 950 fs.
基金Supported by the University of Malaya under Grant No PG100-2014B
文摘We demonstrate a Q-switched ytterbium-doped fiber laser （YDFL） using a newly developed multi-layer black phosphorous （BP） saturable absorber （SA）. The BP SA is prepared by mechanically exfoliating a BP crystal and sticking the acquired BP flakes onto a scotch tape. A small piece of the tape is then placed between two ferrules and incorporated in a YDFL cavity to achieve a stable Q-switched operation in a 1.0 μm region. The laser has a pump threshold of 55.1 mW, a pulse repetition rate that is tunable from 8.2 to 32.9 kHz, and the narrowest pulse width of 10.8 μs. The highest pulse energy of 328 nJ is achieved at the pump power of 97.6 mW. Our results show that multi-layer BP is a promising SA for Q-switching laser operation.
基金Supported by Makkah Eye Hospital and Health Insurance Corporation,Khartoum State(HIKS)
文摘AIM： To assess the frequency and associated risk fac- tors of diabetic retinopathy among Sudanese individuals with diabetes attending Makka Eye complex in Khartoum, Sudan. METHODS： The cross sectional hospital based study recruited 316 individuals with diabetes from Makkah Eye Complex Retina Clinic. Standard questionnaire was used to collect demographic data, medical history and life style characteristics. Blood samples were taken to measure HbAlc and lipid profile. Fundus and slit lamp examination were performed for screening of diabetic retinopathy. RESULTS： Among 316 participants, 187 （59.2%） were males and 129 （40.8%） were females. The mean age of participants was 58.7＋_10.5y. The overall frequency of retinopathy was 261 （82.6%）. The percentages of the total participants with proliferative diabetic retinopathy （PDR） were 126 （39.9%） and non-proliferative diabetic retinopathy （NPDR） were 135 （42.7%）. importantly, duration of diabetes mellitus （DM） （72.2% of more than 10y）, being on oral hypoglycaemic drugs （versus insulin）, and hypertension were all significant risk factors for diabetic retinopathy （P=0.00, 0.01 and 0.00 respectively）. Complications ofdiabetes like diabetic foot （17.7%）, history of amputation （6.7%） and clinically significant macular edema （CSME） （47.4%） of the eyes were all significant risk factors （P〈0.05）. Logistic regression analysis showed that duration of diabetes, hypertension and CSME were found to be absolute risk factors （P=-0.007, 0.003 and 0,000 respectively）. Duration of DM of more than 10y have more than double risk （OR--2.8）, while having hypertension triples the risk of retinopathy （OR=3.1）. CONCLUSION： High rates of diabetic retinopathy are noted among individuals with diabetes attending Makkah Eye hospital in capital Khartoum. Urgent strategies are needed to monitor and treat hypertension and optimize diabetes control in individuals with diabetes. More investment in diabetes services is
