色林错湖位于青藏高原内部,是西藏第一大咸水内陆湖。研究区剖面选自色林错第三湖泊阶地,利用常用气候替代指标色度,结合粒度、碳酸盐含量[CaCO3(%)]、矿物分析和全有机质(TOC)等进行对比分析,同时采用14C测年方法对剖面进行准确的年代...色林错湖位于青藏高原内部,是西藏第一大咸水内陆湖。研究区剖面选自色林错第三湖泊阶地,利用常用气候替代指标色度,结合粒度、碳酸盐含量[CaCO3(%)]、矿物分析和全有机质(TOC)等进行对比分析,同时采用14C测年方法对剖面进行准确的年代划分,初步探讨了末次冰盛期以来色林错湖泊沉积物色度增强机制的差异性。研究表明:a*、b*与中粗粒砂、磁化率具有较好的相关性;亮度L*与CaCO3(%)具较好相关性;因而沉积物色度变化可反应区域古气候变化。同时对湖泊沉积物矿物分析发现,影响色度变化的制色矿物主要是针铁矿,且以还原环境为主。红度a*高值与亮度L*低值对应气候暖湿气候环境,沉积物粒度较粗,碳酸盐含量低,有机质含量高,磁化率较高值;反之,红度a*低值,L*高值,粒度较细,碳酸盐含量高,有机质含量低,磁化率低值,对应干冷气候。在17.4~15.5 cal ka BP阶段,对应干冷的气候特点;在15.5~10.4 cal ka BP阶段,对应温暖湿润的气候;在10.4~5.2 cal ka BP阶段,整体属于温暖湿润的气候特点;其中,在9.7~9.4 cal ka BP和8.75~8.5 cal ka BP为两个重要的冷事件,属于干湿的气候特点;在5.2~1.2 cal ka BP阶段,反映了干冷的气候特征;在4.3~4.0 cal ka BP,3.3~3.0 cal ka BP和2.4~1.75 cal ka BP,反映了干旱温暖的气候特点;在1.2 cal ka BP以后,色林错湖湖水迅速下降。展开更多
Three-dimensional （3D） hierarchical Pt-Cu tetragonal, highly branched, and dendritic superstructures have been synthesized by a facile template-free hydrothermal approach, showing growth patterns along （111, 110）,...Three-dimensional （3D） hierarchical Pt-Cu tetragonal, highly branched, and dendritic superstructures have been synthesized by a facile template-free hydrothermal approach, showing growth patterns along （111, 110）, （111）, and （100） planes, respectively. These structures have been characterized by transmission electron microscopy （TEM）, X-ray diffraction （XRD）, energy dispersive X-ray spectroscopy （EDX）, inductively coupled plasma optical emission spectrometry （ICP-OES） and a detailed formation mechanism has been developed, which shows that the in situ formed 12 and the galvanic replacement reaction between Cu and Pt4, may guide the formation of these superstructures. The comparative electrocatalytic properties have been investigated for methanol and ethanol oxidation. Due to their interconnected arms, sufficient absorption sites, and exposed surfaces, these superstructures exhibit enhanced electrocatalytic performance for electro-oxidation of methanol and ethanol when compared with commercial Pt/C and Pt black.展开更多
Traditionally, the success of a researcher is assessed by the number of publications he or she publishes in peer-reviewed, indexed, high impact journals. This essential yardstick, often referred to as the impact of a ...Traditionally, the success of a researcher is assessed by the number of publications he or she publishes in peer-reviewed, indexed, high impact journals. This essential yardstick, often referred to as the impact of a specific researcher, is assessed through the use of various metrics. While researchers may be acquainted with such matrices, many do not know how to use them to enhance their careers. In addition to these metrics, a number of other factors should be taken into consideration to objectively evaluate a scientist＇s profile as a researcher and academician. Moreover, each metric has its own limitations that need to be considered when selecting an appropriate metric for evaluation. This paper provides a broad overview of the wide array of metrics currently in use in academia and research. Popular metrics are discussed and defined, including traditional metrics and article-level metrics, some of which are applied to researchers for a greater understanding of a particular concept, including varicocete that is the thematic area of this Special Issue of Asian Journal of Andrology. We recommend the combined use of quantitative and qualitative evaluation using judiciously selected metrics for a more objective assessment of scholarly output and research impact.展开更多
Wild cotton species can contribute a valuable gene pool for agronomically desirable cultivated tetraploid cultivars. In order to exploit diploid cotton a regeneration system is required to achieve transformation based...Wild cotton species can contribute a valuable gene pool for agronomically desirable cultivated tetraploid cultivars. In order to exploit diploid cotton a regeneration system is required to achieve transformation based goals. The present studies aimed at optimizing the conditions for regeneration of local varieties as well as wild species of cotton. Different callus induction media were tested with varying concentrations of hormones in which sucrose was used as nutritional source. Different explants (hypo-cotyls, cotyledon, root) were used to check the regeneration of both local cotton plants and wild relatives using T & G medium, BAP medium, CIM medium, EMMS medium, and cell suspension medium. Different stages of embryogenicity such as early torpedo stage, late torpedo stage, heart stage, globular stage and cotyledonary stage were observed in wild relatives of cotton. The results of this study pave the way for establishing future transformation methods.展开更多
AIM:To assess the relationship between preoperative computed tomography(CT)and postoperative pathological measurements of esophageal tumor length and the prognostic significance of CT tumor length data.METHODS:A retro...AIM:To assess the relationship between preoperative computed tomography(CT)and postoperative pathological measurements of esophageal tumor length and the prognostic significance of CT tumor length data.METHODS:A retrospective study was carried out in 56 patients who underwent curative esophagogastrectomy.Tumor lengths were measured on the immediate preoperative CT and on the post-operative resection specimens.Inter-and intra-observer variations in CT measurements were assessed.Survival data were collected.RESULTS:There was a weak correlation between CT and pathological tumor length(r=0.30,P=0.025).CT lengths were longer than pathological lengths in 68%(38/56)of patients with a mean difference of 1.67 cm(95%CI:1.18-2.97).The mean difference in measurements by two radiologists was 0.39 cm(95% CI:-0.59-1.44).The mean difference between repeat CT measured tumor length(intra-observer variation) were 0.04 cm(95%CI:-0.59-0.66)and 0.47 cm (95%CI:-0.53-1.47).When stratified,patients not receiving neoadjuvant chemotherapy showed a strong correlation between CT and pathological tumor length(r =0.69,P=0.0014,n=37)than patients that did(r= 0.13,P=0.43,n=19).Median survival with CT tumor length>5.6 cm was poorer than with smaller tumors,but the difference was not statistically significant.CONCLUSION:Esophageal tumor length assessed using CT does not reflect pathological tumor extent and should not be the only modality used for management decisions,particularly for planning radiotherapy.展开更多
Microbiologically influenced corrosion(MIC) is a big threat to the strength and safety of many metallic materials used in different environments throughout the world. The metabolites and bioactivity of the microorgani...Microbiologically influenced corrosion(MIC) is a big threat to the strength and safety of many metallic materials used in different environments throughout the world. The metabolites and bioactivity of the microorganisms cause severe deterioration on the metals. In this study, MIC of pure titanium(Ti) was studied in the presence of a highly corrosive aerobic marine bacterium Pseudomonas aeruginosa. The results obtained from electrochemical test showed that Ti was corrosion resistant in the abiotic culture medium after 14 d, while the increased corrosion current density(i_(corr)) obtained from polarization curves and the decreased charge transfer resistance(R_(ct)) from electrochemical impedance spectroscopy(EIS)indicated the accelerated corrosion of Ti caused by P. aeruginosa biofilm. For further confirmation of the above results, the surface of Ti was investigated using scanning electron microscopy(SEM), confocal laser scanning microscopy(CLSM) and X-ray photoelectron spectroscopy(XPS). According to the XPS results, TiO_2 was formed in both abiotic and biotic conditions, while unstable oxide Ti_2O_3 was detected in the presence of P. aeruginosa, leading to the defects in the passive film and localized corrosion. Pitting corrosion was investigated with the help of CLSM, and the largest pit depth found on Ti surface immersed in P. aeruginosa was 1.2 μm. Ti was not immune to MIC caused by P. aeruginosa.展开更多
BACKGROUND Left bundle branch pacing(LBBP)is a novel pacing modality of cardiac resynchronization therapy(CRT)that achieves more physiologic native ventricular activation than biventricular pacing(BiVP).AIM To explore...BACKGROUND Left bundle branch pacing(LBBP)is a novel pacing modality of cardiac resynchronization therapy(CRT)that achieves more physiologic native ventricular activation than biventricular pacing(BiVP).AIM To explore the validity of electromechanical resynchronization,clinical and echocardiographic response of LBBP-CRT.METHODS Systematic review and Meta-analysis were conducted in accordance with the standard guidelines as mentioned in detail in the methodology section.RESULTS In our analysis,the success rate of LBBP-CRT was determined to be 91.1%.LBBP CRT significantly shortened QRS duration,with significant improvement in echocardiographic parameters,including left ventricular ejection fraction,left ventricular end-diastolic diameter and left ventricular end-systolic diameter in comparison with BiVP-CRT.CONCLUSION A significant reduction in New York Heart Association class and B-type natriuretic peptide levels was also observed in the LBBP-CRT group vs BiVP-CRT group.Lastly,the LBBP-CRT cohort had a reduced pacing threshold at follow-up as compared to BiVP-CRT.展开更多
Nickel based super-alloys are widely employed in aircraft engines and gas turbines due to their high temperature strength, corrosion resistance and, excellent thermal fatigue properties. Conversely, these alloys are v...Nickel based super-alloys are widely employed in aircraft engines and gas turbines due to their high temperature strength, corrosion resistance and, excellent thermal fatigue properties. Conversely, these alloys are very difficult to machine and cause rapid wear of the cutting tool, frequent tool changes are thus required resulting in low economy of the machining process. This study provides a detailed review of the t0ol wear mechanism in the machining of nickel based super-alloys. Typical tool wear mechanisms found by different researchers are analyzed in order to find out the most prevalent wear mechanism affecting the tool life. The review of existing works has revealed interesting findings about the tool wear mechanisms in the machining of these alloys. Adhesion wear is found to be the main phenomenon leading to the cutting tool wear in this study.展开更多
Helicity-multiplexed metasurfaces based on symmetric spin–orbit interactions (SOIs) have practical limits because they cannot provide central-symmetric holographic imaging. Asymmetric SOIs can effectively address suc...Helicity-multiplexed metasurfaces based on symmetric spin–orbit interactions (SOIs) have practical limits because they cannot provide central-symmetric holographic imaging. Asymmetric SOIs can effectively address such limitations, with several exciting applications in various fields ranging from asymmetric data inscription in communications to dual side displays in smart mobile devices. Low-loss dielectric materials provide an excellent platform for realizing such exotic phenomena efficiently. In this paper, we demonstrate an asymmetric SOI-dependent transmission-type metasurface in the visible domain using hydrogenated amorphous silicon (a-Si:H) nanoresonators. The proposed design approach is equipped with an additional degree of freedom in designing bi-directional helicity-multiplexed metasurfaces by breaking the conventional limit imposed by the symmetric SOI in half employment of metasurfaces for one circular handedness. Two on-axis, distinct wavefronts are produced with high transmission efficiencies, demonstrating the concept of asymmetric wavefront generation in two antiparallel directions. Additionally, the CMOS compatibility of a-Si:H makes it a cost-effective alternative to gallium nitride (GaN) and titanium dioxide (TiO2) for visible light. The cost-effective fabrication and simplicity of the proposed design technique provide an excellent candidate for high-efficiency, multifunctional, and chip-integrated demonstration of various phenomena.展开更多
We study the Einstein images of a charged Rastall AdS black hole(BH)within the fabric of AdS/CFT correspondence.Considering the holographic setup,we analyze the amplitude of the total response function for various val...We study the Einstein images of a charged Rastall AdS black hole(BH)within the fabric of AdS/CFT correspondence.Considering the holographic setup,we analyze the amplitude of the total response function for various values of model parameters.With an increase in parameterλand temperature T,the amplitude of the response function decreases,while it increases with an increase in electric charge e and chemical potentialμ.The influence of frequencyωalso plays an important role in the bulk field,as it is found that decreasingωleads to an increase in the periods of the waves,which means that the amplitude of the response function also depends on the wave source.The relation between T and the inverse of the horizon for various values of parameterλis interpreted under fixed values of other involved parameters.These,in turn,affect the behavior of the response function and the Einstein ring,which may be used to differentiate the present study from previous ones.We construct the holographic images of the BH in bulk via a special optical system.The results show that the Einstein ring always appears with concentric stripes at the position of the north pole,and this ring transforms into a luminosity-deformed ring or bright light spot when the distant observer lies away from the north pole.Finally,we discuss the influence of the associated parameters on the Einstein ring radius,which is consistent with wave optics.展开更多
Using AdS/CFT correspondence,we analyze the holographic Einstein images via the response function of the complex scalar field as a probe wave on an AdS Schwarzschild scalar-tensor-vector gravity(STVG)black hole(BH).We...Using AdS/CFT correspondence,we analyze the holographic Einstein images via the response function of the complex scalar field as a probe wave on an AdS Schwarzschild scalar-tensor-vector gravity(STVG)black hole(BH).We find that the amplitude of the response function||decreases with increasing values of coupling parameter a and increases with decreasing temperature T.The frequencyωof the wave source also plays a significant role in wave periods;as we increase the values ofω,the periods of waves decrease,indicating that the total response function closely depends on the wave source.Further,we investigate the optical appearance of the holographic images of the BH in bulk.We found that the holographic ring always appears with surrounding concentric stripes when the observer is located at the north pole,and an extremely bright ring appears when the observer is at the position of the photon sphere of the BH.This ring changes into a luminosity-deformed ring or a bright light spot as the observational angle changes.The corresponding brightness profiles show that the luminosity of the ring decreases and the shadow radius increases with increasing values of a.The relation between temperature T and the inverse of the horizonh_e is discussed;T is small at the beginning of the horizon he and then increases as the horizon radius increases.This effect can be used to distinguish the STVG BH solution from other BH solutions.Moreover,these significant features are also reflected in the Einstein ring and corresponding brightness profiles.In addition,we compare the results obtained by wave optics and geometric optics,which align well,implying that the holographic scheme adopted in this study is valid.展开更多
The aim of this review was to evaluate the therapeutic potential of exosomes, extracellular vesicles secreted by cells. They have emerged as potential therapeutic transporters for several diseases. This review provide...The aim of this review was to evaluate the therapeutic potential of exosomes, extracellular vesicles secreted by cells. They have emerged as potential therapeutic transporters for several diseases. This review provides an overview of exosomes’ therapeutic potential in cancer therapy and autoimmune conditions such as Coeliac Disease. The therapeutic effect is that the phospholipid-binding protein ANXA1 improves its anti-inflammatory properties. The review also analyzes the intricate processes of exosome production and composition ability to transport biomolecules such as proteins, microRNAs, and lipids, which promote intercellular communication and alter recipient cell behavior. Exosomes, linked to neurological disorders, cardiovascular disease, and cancer, present the means of targeted drug administration due to their innate specificity. Through genetic engineering and chemical modifications, exosomes can be tailored for specific purposes, demonstrating their versatility in targeted therapy. With ongoing research uncovering their therapeutic potential, exosomes present a promising frontier in novel medical treatments across various health conditions.展开更多
Background: Medical and dental students are at risk of Hepatitis B Virus (HBV) infection. The study aimed to assess the vaccination status against Hepatitis B Virus of students in clinical and non-clinical years of a ...Background: Medical and dental students are at risk of Hepatitis B Virus (HBV) infection. The study aimed to assess the vaccination status against Hepatitis B Virus of students in clinical and non-clinical years of a private medical and dental college, and their knowledge, attitude, and awareness about the subject. Methods: A cross-sectional study was conducted using a pretested, self-administered questionnaire among 203 medical and dental students of CMH Lahore Medical College and Institute of Dentistry (CMH LMC & IOD) in Lahore, Pakistan. Participants were evaluated for their knowledge and vaccination status against Hepatitis B Virus. Students were considered to be fully vaccinated (recipients of 3 doses), partially vaccinated (recipients of 1 or 2 doses), and unvaccinated. Comparisons were made between students of clinical and non-clinical years. Data was entered and analysed using Statistical Package for the Social Sciences (SPSS) version 23. Results: Only 66% (n = 134) of the 203 participants had ever received a Hepatitis B Virus vaccine out of which a meagre 17.2% (n = 35) were fully vaccinated. No significant difference was found in vaccine uptake between students of clinical and non-clinical years (p-value = 0.181) despite significant differences seen in the knowledge of vaccination schedule (p-value = 0.001), the prevalence of needle-stick injuries (p-value = 0.001), and knowledge of protocols to be followed after a needle-stick injury (p-value = 0.001). Conclusion: Our study found that a large proportion of the student population is vulnerable to HBV infection. There is a need to create awareness regarding the subject to increase vaccine uptake. HBV vaccination should be offered to all currently enrolled students and be made mandatory at the time of admission in the future.展开更多
Background: Several conducted studies have reported a higher and more frequent Helicobacter pylori infection rate in type 2 diabetes mellitus (T2DM). The aim of this study was to estimation the prevalence of H. pylori...Background: Several conducted studies have reported a higher and more frequent Helicobacter pylori infection rate in type 2 diabetes mellitus (T2DM). The aim of this study was to estimation the prevalence of H. pylori and its association between H. pylori infection and T2DM. Materials and Methods: A sectional-cross study was conducted based on 200 patients studded with socioeconomic characteristics through a questionnaire & H. pylori was diagnosed by serum anti-H. pylori immunoglobulin G (IgG) and IgA. Furthermore, patients were investigated for fasting blood glucose (FBG) levels, glycosylated hemoglobin (HbA1c), serum cholesterol, and other biochemistry parameters. Results: The findings showed The prevalence of Hp positive infection was significantly higher in the total sample was 134 with (67%). While 66 out of 200 patients with (33%) was H. pylori negative infection. of H. pylori. Further, the mean values were statistically significant for diabetes with H. pylori infection for IgG > 300 titer and IgA > 250 titer, regarding, HbA1C (7.52 ± 0.41) (P Conclusions: The current study revealed that H. pylori prevalence infections were significantly higher in diabetic patients studied compared to non-diabetic patients. Furthermore, T2DM patients infected with H. pylori positive reported a higher prevalence rate of symptoms than H. pylori negative.展开更多
文摘色林错湖位于青藏高原内部,是西藏第一大咸水内陆湖。研究区剖面选自色林错第三湖泊阶地,利用常用气候替代指标色度,结合粒度、碳酸盐含量[CaCO3(%)]、矿物分析和全有机质(TOC)等进行对比分析,同时采用14C测年方法对剖面进行准确的年代划分,初步探讨了末次冰盛期以来色林错湖泊沉积物色度增强机制的差异性。研究表明:a*、b*与中粗粒砂、磁化率具有较好的相关性;亮度L*与CaCO3(%)具较好相关性;因而沉积物色度变化可反应区域古气候变化。同时对湖泊沉积物矿物分析发现,影响色度变化的制色矿物主要是针铁矿,且以还原环境为主。红度a*高值与亮度L*低值对应气候暖湿气候环境,沉积物粒度较粗,碳酸盐含量低,有机质含量高,磁化率较高值;反之,红度a*低值,L*高值,粒度较细,碳酸盐含量高,有机质含量低,磁化率低值,对应干冷气候。在17.4~15.5 cal ka BP阶段,对应干冷的气候特点;在15.5~10.4 cal ka BP阶段,对应温暖湿润的气候;在10.4~5.2 cal ka BP阶段,整体属于温暖湿润的气候特点;其中,在9.7~9.4 cal ka BP和8.75~8.5 cal ka BP为两个重要的冷事件,属于干湿的气候特点;在5.2~1.2 cal ka BP阶段,反映了干冷的气候特征;在4.3~4.0 cal ka BP,3.3~3.0 cal ka BP和2.4~1.75 cal ka BP,反映了干旱温暖的气候特点;在1.2 cal ka BP以后,色林错湖湖水迅速下降。
基金This work was supported by the National Natural Science Foundation of China （Nos. 91127040 and 21221062）, and the State Key Project of Fundamental Research for Nanoscience and Nanotechnology （No. 2011CB932402）.
文摘Three-dimensional （3D） hierarchical Pt-Cu tetragonal, highly branched, and dendritic superstructures have been synthesized by a facile template-free hydrothermal approach, showing growth patterns along （111, 110）, （111）, and （100） planes, respectively. These structures have been characterized by transmission electron microscopy （TEM）, X-ray diffraction （XRD）, energy dispersive X-ray spectroscopy （EDX）, inductively coupled plasma optical emission spectrometry （ICP-OES） and a detailed formation mechanism has been developed, which shows that the in situ formed 12 and the galvanic replacement reaction between Cu and Pt4, may guide the formation of these superstructures. The comparative electrocatalytic properties have been investigated for methanol and ethanol oxidation. Due to their interconnected arms, sufficient absorption sites, and exposed surfaces, these superstructures exhibit enhanced electrocatalytic performance for electro-oxidation of methanol and ethanol when compared with commercial Pt/C and Pt black.
文摘Traditionally, the success of a researcher is assessed by the number of publications he or she publishes in peer-reviewed, indexed, high impact journals. This essential yardstick, often referred to as the impact of a specific researcher, is assessed through the use of various metrics. While researchers may be acquainted with such matrices, many do not know how to use them to enhance their careers. In addition to these metrics, a number of other factors should be taken into consideration to objectively evaluate a scientist＇s profile as a researcher and academician. Moreover, each metric has its own limitations that need to be considered when selecting an appropriate metric for evaluation. This paper provides a broad overview of the wide array of metrics currently in use in academia and research. Popular metrics are discussed and defined, including traditional metrics and article-level metrics, some of which are applied to researchers for a greater understanding of a particular concept, including varicocete that is the thematic area of this Special Issue of Asian Journal of Andrology. We recommend the combined use of quantitative and qualitative evaluation using judiciously selected metrics for a more objective assessment of scholarly output and research impact.
文摘Wild cotton species can contribute a valuable gene pool for agronomically desirable cultivated tetraploid cultivars. In order to exploit diploid cotton a regeneration system is required to achieve transformation based goals. The present studies aimed at optimizing the conditions for regeneration of local varieties as well as wild species of cotton. Different callus induction media were tested with varying concentrations of hormones in which sucrose was used as nutritional source. Different explants (hypo-cotyls, cotyledon, root) were used to check the regeneration of both local cotton plants and wild relatives using T & G medium, BAP medium, CIM medium, EMMS medium, and cell suspension medium. Different stages of embryogenicity such as early torpedo stage, late torpedo stage, heart stage, globular stage and cotyledonary stage were observed in wild relatives of cotton. The results of this study pave the way for establishing future transformation methods.
基金Supported by The local departmental research fund
文摘AIM:To assess the relationship between preoperative computed tomography(CT)and postoperative pathological measurements of esophageal tumor length and the prognostic significance of CT tumor length data.METHODS:A retrospective study was carried out in 56 patients who underwent curative esophagogastrectomy.Tumor lengths were measured on the immediate preoperative CT and on the post-operative resection specimens.Inter-and intra-observer variations in CT measurements were assessed.Survival data were collected.RESULTS:There was a weak correlation between CT and pathological tumor length(r=0.30,P=0.025).CT lengths were longer than pathological lengths in 68%(38/56)of patients with a mean difference of 1.67 cm(95%CI:1.18-2.97).The mean difference in measurements by two radiologists was 0.39 cm(95% CI:-0.59-1.44).The mean difference between repeat CT measured tumor length(intra-observer variation) were 0.04 cm(95%CI:-0.59-0.66)and 0.47 cm (95%CI:-0.53-1.47).When stratified,patients not receiving neoadjuvant chemotherapy showed a strong correlation between CT and pathological tumor length(r =0.69,P=0.0014,n=37)than patients that did(r= 0.13,P=0.43,n=19).Median survival with CT tumor length>5.6 cm was poorer than with smaller tumors,but the difference was not statistically significant.CONCLUSION:Esophageal tumor length assessed using CT does not reflect pathological tumor extent and should not be the only modality used for management decisions,particularly for planning radiotherapy.
基金supportedfinancially by the National Natural Science Foundation of China(No.U1660118)the National Basic Research Program of China(No.2014CB643300)the National Environmental Corrosion Platform(NECP)
文摘Microbiologically influenced corrosion(MIC) is a big threat to the strength and safety of many metallic materials used in different environments throughout the world. The metabolites and bioactivity of the microorganisms cause severe deterioration on the metals. In this study, MIC of pure titanium(Ti) was studied in the presence of a highly corrosive aerobic marine bacterium Pseudomonas aeruginosa. The results obtained from electrochemical test showed that Ti was corrosion resistant in the abiotic culture medium after 14 d, while the increased corrosion current density(i_(corr)) obtained from polarization curves and the decreased charge transfer resistance(R_(ct)) from electrochemical impedance spectroscopy(EIS)indicated the accelerated corrosion of Ti caused by P. aeruginosa biofilm. For further confirmation of the above results, the surface of Ti was investigated using scanning electron microscopy(SEM), confocal laser scanning microscopy(CLSM) and X-ray photoelectron spectroscopy(XPS). According to the XPS results, TiO_2 was formed in both abiotic and biotic conditions, while unstable oxide Ti_2O_3 was detected in the presence of P. aeruginosa, leading to the defects in the passive film and localized corrosion. Pitting corrosion was investigated with the help of CLSM, and the largest pit depth found on Ti surface immersed in P. aeruginosa was 1.2 μm. Ti was not immune to MIC caused by P. aeruginosa.
文摘BACKGROUND Left bundle branch pacing(LBBP)is a novel pacing modality of cardiac resynchronization therapy(CRT)that achieves more physiologic native ventricular activation than biventricular pacing(BiVP).AIM To explore the validity of electromechanical resynchronization,clinical and echocardiographic response of LBBP-CRT.METHODS Systematic review and Meta-analysis were conducted in accordance with the standard guidelines as mentioned in detail in the methodology section.RESULTS In our analysis,the success rate of LBBP-CRT was determined to be 91.1%.LBBP CRT significantly shortened QRS duration,with significant improvement in echocardiographic parameters,including left ventricular ejection fraction,left ventricular end-diastolic diameter and left ventricular end-systolic diameter in comparison with BiVP-CRT.CONCLUSION A significant reduction in New York Heart Association class and B-type natriuretic peptide levels was also observed in the LBBP-CRT group vs BiVP-CRT group.Lastly,the LBBP-CRT cohort had a reduced pacing threshold at follow-up as compared to BiVP-CRT.
文摘Nickel based super-alloys are widely employed in aircraft engines and gas turbines due to their high temperature strength, corrosion resistance and, excellent thermal fatigue properties. Conversely, these alloys are very difficult to machine and cause rapid wear of the cutting tool, frequent tool changes are thus required resulting in low economy of the machining process. This study provides a detailed review of the t0ol wear mechanism in the machining of nickel based super-alloys. Typical tool wear mechanisms found by different researchers are analyzed in order to find out the most prevalent wear mechanism affecting the tool life. The review of existing works has revealed interesting findings about the tool wear mechanisms in the machining of these alloys. Adhesion wear is found to be the main phenomenon leading to the cutting tool wear in this study.
基金This work was financially supported by the LGD-SNU incubation program funded by LG Display and the National Research Foundation of Korea(NRF)grants(NRF-2019R1A2C3003129,CAMM-2019M3A6B3030637,NRF-2019R1A5A8080290)funded by the Ministry of Science and ICT(MSIT)of the Korean government.M.Q.M acknowledges a research grant by Higher Education Commission(HEC)of Pakistan through National Research Program for Universities(NRPU)[Project No.10177/Punjab/NRPU/R&D/HEC/2017]to support this work.M.Q.M.,T.T.,K.R.,U.Y.,and M.Z.acknowledge their internal research grants from ITU.M.A.A.acknowledges the Pre-Doctoral Fellowship from ITU.I.K.acknowledges the NRF Sejong Science fellowship(NRF-2021R1C1C2004291)funded by the MSIT of the Korean government.
文摘Helicity-multiplexed metasurfaces based on symmetric spin–orbit interactions (SOIs) have practical limits because they cannot provide central-symmetric holographic imaging. Asymmetric SOIs can effectively address such limitations, with several exciting applications in various fields ranging from asymmetric data inscription in communications to dual side displays in smart mobile devices. Low-loss dielectric materials provide an excellent platform for realizing such exotic phenomena efficiently. In this paper, we demonstrate an asymmetric SOI-dependent transmission-type metasurface in the visible domain using hydrogenated amorphous silicon (a-Si:H) nanoresonators. The proposed design approach is equipped with an additional degree of freedom in designing bi-directional helicity-multiplexed metasurfaces by breaking the conventional limit imposed by the symmetric SOI in half employment of metasurfaces for one circular handedness. Two on-axis, distinct wavefronts are produced with high transmission efficiencies, demonstrating the concept of asymmetric wavefront generation in two antiparallel directions. Additionally, the CMOS compatibility of a-Si:H makes it a cost-effective alternative to gallium nitride (GaN) and titanium dioxide (TiO2) for visible light. The cost-effective fabrication and simplicity of the proposed design technique provide an excellent candidate for high-efficiency, multifunctional, and chip-integrated demonstration of various phenomena.
基金Supported by the National Natural Science Foundation of China (11675140,11705005,12375043)the Innovation and Development Joint Foundation of Chongqing Natural Science Foundation (CSTB2022NSCQ-LZX0021)the Basic Research Project of Science and Technology Committee of Chongqing (CSTB2023NSCQ-MSX0324)。
文摘We study the Einstein images of a charged Rastall AdS black hole(BH)within the fabric of AdS/CFT correspondence.Considering the holographic setup,we analyze the amplitude of the total response function for various values of model parameters.With an increase in parameterλand temperature T,the amplitude of the response function decreases,while it increases with an increase in electric charge e and chemical potentialμ.The influence of frequencyωalso plays an important role in the bulk field,as it is found that decreasingωleads to an increase in the periods of the waves,which means that the amplitude of the response function also depends on the wave source.The relation between T and the inverse of the horizon for various values of parameterλis interpreted under fixed values of other involved parameters.These,in turn,affect the behavior of the response function and the Einstein ring,which may be used to differentiate the present study from previous ones.We construct the holographic images of the BH in bulk via a special optical system.The results show that the Einstein ring always appears with concentric stripes at the position of the north pole,and this ring transforms into a luminosity-deformed ring or bright light spot when the distant observer lies away from the north pole.Finally,we discuss the influence of the associated parameters on the Einstein ring radius,which is consistent with wave optics.
基金Supported by the National Natural Science Foundation of China(11675140,11705005,12375043)the Innovation and Development Joint Foundation of Chongqing Natural Science Foundation(CSTB2022NSCQ-LZX0021)the Basic Research Project of Science and Technology Committee of Chongqing(CSTB2023NSCQ-MSX0324)。
文摘Using AdS/CFT correspondence,we analyze the holographic Einstein images via the response function of the complex scalar field as a probe wave on an AdS Schwarzschild scalar-tensor-vector gravity(STVG)black hole(BH).We find that the amplitude of the response function||decreases with increasing values of coupling parameter a and increases with decreasing temperature T.The frequencyωof the wave source also plays a significant role in wave periods;as we increase the values ofω,the periods of waves decrease,indicating that the total response function closely depends on the wave source.Further,we investigate the optical appearance of the holographic images of the BH in bulk.We found that the holographic ring always appears with surrounding concentric stripes when the observer is located at the north pole,and an extremely bright ring appears when the observer is at the position of the photon sphere of the BH.This ring changes into a luminosity-deformed ring or a bright light spot as the observational angle changes.The corresponding brightness profiles show that the luminosity of the ring decreases and the shadow radius increases with increasing values of a.The relation between temperature T and the inverse of the horizonh_e is discussed;T is small at the beginning of the horizon he and then increases as the horizon radius increases.This effect can be used to distinguish the STVG BH solution from other BH solutions.Moreover,these significant features are also reflected in the Einstein ring and corresponding brightness profiles.In addition,we compare the results obtained by wave optics and geometric optics,which align well,implying that the holographic scheme adopted in this study is valid.
文摘The aim of this review was to evaluate the therapeutic potential of exosomes, extracellular vesicles secreted by cells. They have emerged as potential therapeutic transporters for several diseases. This review provides an overview of exosomes’ therapeutic potential in cancer therapy and autoimmune conditions such as Coeliac Disease. The therapeutic effect is that the phospholipid-binding protein ANXA1 improves its anti-inflammatory properties. The review also analyzes the intricate processes of exosome production and composition ability to transport biomolecules such as proteins, microRNAs, and lipids, which promote intercellular communication and alter recipient cell behavior. Exosomes, linked to neurological disorders, cardiovascular disease, and cancer, present the means of targeted drug administration due to their innate specificity. Through genetic engineering and chemical modifications, exosomes can be tailored for specific purposes, demonstrating their versatility in targeted therapy. With ongoing research uncovering their therapeutic potential, exosomes present a promising frontier in novel medical treatments across various health conditions.
基金financially supported by the National Key R&D Program of China (2017YFA0207202)the National Natural Science Foundation of China (52073230)+1 种基金the Joint Research Funds of Department of Science&Technology of Shaanxi Province and Northwestern Polytechnical University (2020GXLH-Z-013)the Fundamental Research Funds for the Central Universities。
文摘Background: Medical and dental students are at risk of Hepatitis B Virus (HBV) infection. The study aimed to assess the vaccination status against Hepatitis B Virus of students in clinical and non-clinical years of a private medical and dental college, and their knowledge, attitude, and awareness about the subject. Methods: A cross-sectional study was conducted using a pretested, self-administered questionnaire among 203 medical and dental students of CMH Lahore Medical College and Institute of Dentistry (CMH LMC & IOD) in Lahore, Pakistan. Participants were evaluated for their knowledge and vaccination status against Hepatitis B Virus. Students were considered to be fully vaccinated (recipients of 3 doses), partially vaccinated (recipients of 1 or 2 doses), and unvaccinated. Comparisons were made between students of clinical and non-clinical years. Data was entered and analysed using Statistical Package for the Social Sciences (SPSS) version 23. Results: Only 66% (n = 134) of the 203 participants had ever received a Hepatitis B Virus vaccine out of which a meagre 17.2% (n = 35) were fully vaccinated. No significant difference was found in vaccine uptake between students of clinical and non-clinical years (p-value = 0.181) despite significant differences seen in the knowledge of vaccination schedule (p-value = 0.001), the prevalence of needle-stick injuries (p-value = 0.001), and knowledge of protocols to be followed after a needle-stick injury (p-value = 0.001). Conclusion: Our study found that a large proportion of the student population is vulnerable to HBV infection. There is a need to create awareness regarding the subject to increase vaccine uptake. HBV vaccination should be offered to all currently enrolled students and be made mandatory at the time of admission in the future.
文摘Background: Several conducted studies have reported a higher and more frequent Helicobacter pylori infection rate in type 2 diabetes mellitus (T2DM). The aim of this study was to estimation the prevalence of H. pylori and its association between H. pylori infection and T2DM. Materials and Methods: A sectional-cross study was conducted based on 200 patients studded with socioeconomic characteristics through a questionnaire & H. pylori was diagnosed by serum anti-H. pylori immunoglobulin G (IgG) and IgA. Furthermore, patients were investigated for fasting blood glucose (FBG) levels, glycosylated hemoglobin (HbA1c), serum cholesterol, and other biochemistry parameters. Results: The findings showed The prevalence of Hp positive infection was significantly higher in the total sample was 134 with (67%). While 66 out of 200 patients with (33%) was H. pylori negative infection. of H. pylori. Further, the mean values were statistically significant for diabetes with H. pylori infection for IgG > 300 titer and IgA > 250 titer, regarding, HbA1C (7.52 ± 0.41) (P Conclusions: The current study revealed that H. pylori prevalence infections were significantly higher in diabetic patients studied compared to non-diabetic patients. Furthermore, T2DM patients infected with H. pylori positive reported a higher prevalence rate of symptoms than H. pylori negative.
