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Wai-Man Tang Anthropology Department, The Chinese University of Hong Kong, Hong Kong Abstract: A recent survey has shown that Nepali drug users in Hong Kong tend to have a low rate of usage of day-care and residential rehabilitation services, but a high rate of usage of methadone services. Little is known about the reasons behind such a pattern. Therefore, in this study, a 12-month ethnographic examination has been implemented in three sites, including a day-care center, residential rehabilitation center, and methadone clinic, to explore the experiences of 20 Nepali drug users in their use of drug-related services in Hong Kong and to examine the relationship between ethnicity and the use of drug-related services. The result shows that the reason for this pattern of service use is related to the approach of the services and the cultural perception of the service providers about the service users. The day-care and residential rehabilitation services emphasize an integrated approach, but the staff tend to overlook the heterogeneity of their clients, for example, the differences in caste and sex, and fail to provide suitable services to them, whereas the methadone service follows a biomedical model, which seldom addresses the social characteristics of the service users, which in turn minimizes the opportunity for misunderstandings between the staff and the clients. This research shows that ethnicity is a significant factor in drug treatment and that culture-specific treatment that takes into consideration the treatment approach and the heterogeneity of the clients is strongly needed. Keywords: methadone, residential rehabilitation services, drug treatment, ethnicity, Nepalis

Toroidal plasma flow driven by turbulent torque associated with nonlinear residual stress generation is shown to recover the observed key features of intrinsic rotation in experiments. Specifically, the turbulence-driven intrinsic rotation scales close to linearly with plasma gradients and the inverse of the plasma current, qualitatively reproducing empirical scalings obtained from a large experimental data base. The effect of magnetic shear on the symmetry breaking in the parallel wavenumber spectrum is identified. The origin of the current scaling is found to be the enhanced k symmetry breaking induced by increased radial variation of the safety factor as the current decreases. The physics origin for the linear dependence of intrinsic rotation on the pressure gradient comes from the fact that both turbulence intensity and the zonal flow shear, which are two key ingredients for driving the residual stress, are increased with the strength of the turbulence drives, which are R /L Te and R/Lne for the collisionless trapped electron mode (CTEM). Highlighted results also include robust radial pinches in toroidal flow, heat and particle transport driven by CTEM turbulence, which emerge in phase, and are shown to play important roles in determining plasma profiles. Also discussed are the experimental tests proposed to validate findings from these gyrokinetic simulations. © 2011 American Institute of Physics.

Global gyrokinetic simulations have revealed an important nonlinear flow generation process due to the residual stress produced by electrostatic turbulence of ion temperature gradient (ITG) modes and trapped electron modes (TEMs). In collisionless TEM (CTEM) turbulence, nonlinear residual stress generation by both the fluctuation intensity and the intensity gradient in the presence of broken symmetry in the parallel wavenumber spectrum is identified for the first time. Concerning the origin of the symmetry breaking, turbulence self-generated low frequency zonal flow shear has been identified to be a key, universal mechanism in various turbulence regimes. Simulations reported here also indicate the existence of other mechanisms beyond E×B shear. The ITG turbulence driven "intrinsic" torque associated with residual stress is shown to increase close to linearly with the ion temperature gradient, in qualitative agreement with experimental observations in various devices. In CTEM dominated regimes, a net toroidal rotation is driven in the cocurrent direction by intrinsic torque, consistent with the experimental trend of observed intrinsic rotation. The finding of a "flow pinch" in CTEM turbulence may offer an interesting new insight into the underlying dynamics governing the radial penetration of modulated flows in perturbation experiments. Finally, simulations also reveal highly distinct phase space structures between CTEM and ITG turbulence driven momentum, energy, and particle fluxes, elucidating the roles of resonant and non-resonant particles. © 2010 American Institute of Physics.

A significant inward flux of toroidal momentum is found in global gyrokinetic simulations of ion temperature gradient turbulence, leading to core plasma rotation spin-up. The underlying mechanism is identified to be the generation of residual stress due to the k parallel symmetry breaking induced by global quasistationary zonal flow shear. Simulations also show a significant off-diagonal element associated with the ion temperature gradient in the neoclassical momentum flux, while the overall neoclassical flux is small. In addition, the residual turbulence found in the presence of strong E x B flow shear may account for neoclassical-level ion heat and anomalous momentum transport widely observed in experiments.

A significant inward flux of toroidal momentum is found in global gyrokinetic simulations of ion temperature gradient turbulence, leading to core plasma rotation spin-up. The underlying mechanism is identified to be the generation of residual stress due to the k parallel symmetry breaking induced by global quasistationary zonal flow shear. Simulations also show a significant off-diagonal element associated with the ion temperature gradient in the neoclassical momentum flux, while the overall neoclassical flux is small. In addition, the residual turbulence found in the presence of strong E x B flow shear may account for neoclassical-level ion heat and anomalous momentum transport widely observed in experiments.

Experiments with plasmas having nearly equal concentrations of deuterium and tritium have been carried out on TFTR. To date (September 1995), the maximum fusion power has been 10.7 MW, using 39.5 MW of neutral beam heating, in a supershot discharge and 6.7 MW in a high beta P discharge following a current ramp-down. The fusion power density in the core of the plasma has reached 2.8 MW/m3, exceeding that expected in the International Thermonuclear Experimental Reactor (ITER). The energy confinement time tau E is observed to increase in DT, relative to D plasmas, by 20% and the n1(0).T1(0). tau E product by 55%. The improvement in thermal confinement is caused primarily by a decrease in ion heat conductivity in both supershot and limiter H mode discharges. Extensive lithium pellet injection increased the confinement time to 0.27 s and enabled higher current operation in both supershot and high beta P discharges. First measurements of the confined alpha particles have been performed and found to be in good agreement with TRANSP simulations assuming classical confinement. Measurements of the alpha ash profile have been compared with simulations using particle transport coefficients from helium gas puffing experiments. The loss of energetic alpha particles to a detector at the bottom of the vessel is well described by the first-orbit loss mechanism. No loss due to alpha particle driven instabilities has yet been observed. ICRF heating of a DT plasma, using the second harmonic of tritium, has been demonstrated. DT experiments on TFTR will continue both to explore the physics underlying the ITER design and to examine some of the physics issues associated with an advanced tokamak reactor.

Steady-state and perturbative transport analysis are complementary techniques for the study of transport in tokamaks. These techniques are applied to the investigation of auxiliary-heated L-mode and supershot plasmas in the tokamak fusion test reactor (TFTR) [R. J. Hawryluk et al., Plasma Physics and Controlled Nuclear Fusion Research, Proceedings of the 11th International Conference, Kyoto, 1986 (IAEA, Vienna, 1987), Vol. 1, p. 51.]. In the L mode, both steady-state and perturbative transport measurements reveal a strong temperature dependence that is consistent with electrostatic microinstability theory and the degradation of confinement with neutral beam power. Steady-state analysis of the ion heat and momentum balance in supershots indicates a reduction and a significant weakening of the power-law dependence on the transport in the center of the discharge. © 1991 American Institute of Physics.

Anteroposterior radiographs that included the whole tibia were taken before and after 75 total knee arthroplasties in 48 patients. The same tibial extra-medullary alignment guide system was used in every knee. The average tibial component alignment was 0.4 (SD 2.5, range -4.9 to 6.4) degrees of valgus post-operatively. 59 tibial components (78.7%) had a tibial cut within 3 degrees from being perpendicular to the mechanical axis, ten were too valgus (13.3%) and six were too varus (8%). The chance of the tibial components becoming too varus was higher if there was lateral tibial bowing, compared with no tibial bowing (p=0.048). A smaller lateral width of the leg increased the chance of the tibial components becoming too valgus (p=0.047). [ABSTRACT FROM AUTHOR]

Background: The usefulness of the PFA-100 in assessing the risk of bleeding in non-cardiac surgery is not clear. This study aims to examine this by correlating preoperative PFA-100 measurement with perioperative bleeding in patients receiving cyclooxygenase (COX) inhibitors.Methods: PFA-100 with adenosine-5'-diphosphate (ADPCT) and epinephrine (EPICT) cartridges were measured before operation in consecutive patients undergoing elective total knee replacement and taking different COX inhibitors. Surgery and anaesthesia were performed by the same team using standardized techniques. Intraoperative blood loss and postoperative drain output were recorded by anaesthetists and nurses blinded to the PFA-100 measurements. Surgeons, similarly blinded, were asked to rate the quality of haemostasis. Correlation was sought between these data and PFA-100 measurements.Results: Thirty patients were studied, involving 51 knees. Preoperative PFA-100 EPICT was correlated with drain output (r=0.30, P=0.03). The correlation becomes stronger when a 20% in vitro haemodiluted sample was used for measurement (r=0.42, P=0.01). Receiver-operating characteristic curve analysis using the diluted measurements [area under curve (AUC) 0.74 (95% CI 0.54-0.94)] suggested using a cut-off value of 188 s for EPICT, which will predict excessive drain output with 89% sensitivity, 54% specificity, and a likelihood ratio of 1.93. Diluted EPICT was also correlated with surgeon rating of haemostasis (r=0.36, P=0.04) although none of the measurements correlated with intraoperative blood loss.Conclusions: Preoperative PFA-100 prolongation is correlated with increased postoperative drain output. It can be a potentially useful preoperative measurement in patients taking COX inhibitors. [ABSTRACT FROM AUTHOR]

The neuromorphic vision system that utilizes spikes as information carriers is crucial for the formation of spiking neural networks. Here, we present a bioinspired flexible artificial spiking photoreceptor (ASP), which is realized by using a single VO 2 Mott memristor that can simultaneously sense and encode the stimulus light into spikes. The ASP has high spike-encoded photosensitivity and ultrawide photosensing range (405-808 nm) with good endurance (>7 × 10 7 ) and high flexibility (bending radius ∼5 mm). Then, we put forward an all-spike electronic retina architecture that comprises one layer of ASPs and one layer of artificial optical nerves (AONs) to process the spike information. Each AON consists of a single Mott memristor connected in series with a neuro-transistor that is a multiple-input floating-gate MOS transistor. Simulation results demonstrate that the all-spike electronic retina can successfully segment images with high Shannon entropy, thus laying the foundation for the development of a spike-based neuromorphic vision system.

Objective: To evaluate the effect of social media based behavioral intervention on promoting joint testing of HIV and syphilis in young men who have sex with men (MSM). Methods: After the recruitment, the participants who met the inclusion criteria were randomly divided (1∶1) into two groups, i.e. social media intervention group and control group. The control group was given routine voluntary counseling and testing (VCT) services. The intervention group was also given VCT services, besides; the comprehensive strategies through social media, including regular health education message and testing information sending, were given to them to strengthen the behavioral intervention. Follow up was conducted for the participants for 12 months after the intervention. The number and the proportion of young MSM receiving HIV and syphilis testing, and the reported proportion of the young MSM with sexually transmitted diseases (STD) symptoms between the intervention group and the control group were compared to evaluate the effect of the intervention. Results: A total of 315 young MSM were recruited (158 in the intervention group and 157 in the control group), in whom 248 young MSM completed the follow up. The follow-up rate was 78.7%. There was no significant difference in baseline characteristics between the intervention group and the control group (all P >0.05). The proportion of young MSM receiving more than one joint testing in the intervention group was slightly higher than that in the control group (53.2% vs. 48.4%, rate difference (RD): 4.8%, 95% CI : -7.5%-17.0%, P =0.448) without significant difference. However, in the young MSM who used condoms in the last anal sex, the proportion of those receiving more than one joint testing in the intervention group was higher than that in the control group (63.8% vs. 46.1%, RD: 17.7%, 95% CI : 1.5%-32.6%, P =0.035). In addition, the reported proportion of young MSM with STD symptoms in the intervention group was significantly lower than that in the control group (6.3% vs. 18.0%,RD: -11.7%, 95% CI : -20.6%- -3.0%, P =0.005). Conclusion: Compared with routine VCT, social media based behavioral intervention might promote joint HIV and syphilis testing in the young MSM who used condom in the study. It could significantly reduce the reporting proportion of STD symptoms, suggesting that this method can promote the AIDS and STD prevention related behaviors in young MSM.

When processed at a low temperature of 200 °C, organic thin-film transistors (OTFTs) with pentacene channel adopting high-k Neodymium-Titanium oxynitride mixtures (NdTiON) with various Ti contents as gate dielectrics are fabricated. The Ti content in the NdTiON is varied by co-sputtering a Ti target at 0 W, 10 W, 20 W and 30 W, respectively, while fixing the sputtering power of an Nd target at 45 W. High-performance OTFT is obtained for the 20 W-sputtered Ti, including a small threshold voltage of -0.71 V and high carrier mobility of 1.70 cm 2 /V·s. The mobility improvement for the optimal Ti content can be attributed to smoother dielectric surface and resultant larger overlying pentacene grains as reflected by Atomic Force Microscopy measurements. Moreover, this sample with the optimal Ti content shows much higher mobility than its counterpart processed at a higher temperature of 400 °C (0.8 cm 2 /V·s) because it has a thinner gate-dielectric/gate-electrode interlayer for stronger screening on the remote phonon scattering by the gate electrode. In addition, a high dielectric constant of around 10 is obtained for the NdTiON gate dielectric that contributes to a threshold voltage smaller than 1 V for the pentacene OTFT, implying the high potential of the Nd-Ti oxynitride in future high-performance organic devices.

Objectives: Determine 90-day mortality of mechanically ventilated ward patients outside the intensive care unit (ICU) and its association with organisational factors., Design: Multicentre prospective observational study of mechanically ventilated ward patients. Modified Poisson regression was used to assess association between nurse to patient ratio (NPR) and 90-day mortality, adjusted for designated medical team, Society of Critical Care Medicine (SCCM) triage priority and centre effect. NPR was divided into low (1:9.6 to 1:10), medium (1:6 to 1:8) and high (1:2.6). Sensitivity analysis was conducted for pneumonia with or without acute respiratory distress syndrome (ARDS) to assess magnitude of association., Setting: 7 acute public hospitals in Hong Kong., Participants: All 485 mechanically ventilated patients in wards from participating hospitals between 18 January 2016 and 17 April 2016 were recruited. Three hundred patients were included after excluding patients with limitation of therapy within 24 hours of intubation., Main Outcomes: 90-day mortality, Mortality Prediction Model III Standardised mortality ratio (MPMIII 0 SMR)., Results: 201 patients died within 90 days after intubation (67.0%, 95% CI 61.5% to 72.1%), with MPMIII 0 SMR 1.88, 95% CI 1.63 to 2.17. Compared with high NPR, medium and low NPRs were associated with higher risk of 90-day mortality (adjusted relative risk (RR adj ) 1.84, 95% CI 1.70 to 1.99 and 1.64, 95% CI 1.47 to 1.83, respectively). For 114 patients with pneumonia with or without ARDS, low to medium NPR, too sick to benefit from ICU (SCCM priority 4b), no ICU consultation and designated medical team were associated with risk of 90-day mortality (RR adj 1.49, 95% CI 1.40 to 1.58; RR adj 1.60, 95% CI 1.49 to 1.72; RR adj 1.34, 95% CI 1.27 to 1.40; RR adj 0.85, 95% CI 0.78 to 0.93, respectively)., Conclusion: The 90-day mortality rates of mechanically ventilated ward patients were high. NPR was an independent predictor of survival for mechanically ventilated ward patients., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2021. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Female sex workers (FSW) are highly susceptible to chlamydia and gonorrhea infection. However, there is limited literature examining their testing uptake to date. This study aimed to assess the uptake and determinants of chlamydia and gonorrhea testing among FSW in Southern China., Methods: A cross-sectional study with convenience sampling was performed in five cities in Southern China. Data on socio-demographic characteristics, sexual behaviors, chlamydia and gonorrhea testing, and the utilization of health care services from participants were collected through face-to-face interviews. Univariate and multivariable logistic regressions were used to determine factors associated with chlamydia and gonorrhea testing, respectively., Results: Overall, 1207 FSWs were recruited, with the mean age of 30.7 ± 6.8 years and an average number of clients of 7.0 (4.0-10.0) per week. 65.4% participants constantly used condoms with clients during the past month. Only 7.5 and 10.4% had been tested for chlamydia and gonorrhea in the last year, respectively. Multivariable analysis indicated that FSW who worked at low tiers (adjusted Odds Ratio (aOR) = 2.36, 95%CI:1.23-10.14), had more clients in the last month (aOR = 1.03, 95%CI:1.01-1.05), used condoms consistently (aOR = 1.79, 95%CI:1.12-2.86), had STD symptoms (aOR = 4.09,95%CI:2.62-6.40), had been tested for HIV (aOR = 5.16, 95%CI:3.21-8.30) or syphilis (aOR = 6.90, 95%CI:4.21-11.22) in the last year were more likely to have chlamydia testing. In addition, FSW who had more clients in the past month (aOR = 1.02,95%CI:1.00-1.04), had STD symptoms (aOR = 3.33, 95%CI:2.03-5.46), had been tested for HIV (aOR = 3.94, 95%CI:2.34-6.65) and syphilis (aOR = 3.27, 95%CI:1.96-5.46) in the last year were more likely to have gonorrhea testing., Conclusions: The testing rates of chlamydia and gonorrhea are low among Chinese FSW. Integrating chlamydia and gonorrhea testing into HIV testing promotion programs may help bridge the gap among FSW., (© 2021. The Author(s).)

Background: In the "treat all" era, there are few data on the nature of HIV clinical progression in middle-income countries. The aim of the current study was to prospectively analyze the clinical progression of HIV and its indicators among men in China with acute HIV who have sex with men., Methods: From 2009-2014 a total of 400 men with acute HIV infection (AHI) were identified among 7,893 men who have sex with men via periodic pooled nucleic acid amplification testing, and they were assigned to an AHI prospective cohort in Beijing and Shenyang, China. Rapid progression was defined as two consecutive CD4 + T cell counts < 350/µL within 3-24 months post-infection. Kaplan-Meier and Cox-regression analyses were conducted to identify predictors of rapid progression., Results: Among 400 men with AHI 46.5% were rapid progressors, 35.1% reached rapid progressor status by 12 months post-infection, and 63.9% reached rapid progressor status by 24 months. Rapid progression was associated with herpes simplex-2 virus coinfection (adjusted hazard ratio [aHR] 1.7, 95% confidence interval [CI] 1.2-2.3], depression (aHR 1.9, 95% CI 1.5-2.6), baseline CD4 + T cell count < 500/μL (aHR 3.5, 95% CI 2.4-5.1), higher baseline HIV viral load (aHR 1.6, 95% CI 1.2-2.3), acute symptoms lasting ≥ 2 weeks (aHR 1.6, 95% CI 1.1-2.2), higher body mass index (aHR 0.9, 95% CI 0.9-1.0), higher HIV viral load (aHR 1.7, 95% CI 1.4-2.1), set point viral load at 3 months (aHR 2.0, 95% CI 1.6-2.5), each 100-cell/μL decrease in CD4 + T cell count at 3 months (aHR 2.2, 95% CI 1.9-2.5), and baseline routine blood tests including white blood cell count < 5.32, hemoglobin ≥ 151, mean corpuscular hemoglobin ≥ 30.5, hemoglobin concentration ≥ 342, mean platelet count ≥ 342, lymphocytes ≥ 1.98, and mixed cell count ≥ 0.4 (all p < 0.05)., Conclusion: Almost half of the patients underwent rapid clinical progression within 2 years after HIV infection. A treat-all policy is necessary and should be strengthened globally. Rapid progression was correlated with herpes simplex-2 virus coinfection, depression, low CD4 + T cell counts, and high set point viral load in acute infection stage. Rapid progression can be identified via simple indicators such as body mass index and routine blood test parameters in low and middle-income countries., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Zhang, Huang, Tang, Chu, Hu, Liu, Ding, Han, Zhang, Jiang, Geng, Xia, Xu and Shang.)

Purpose: Microvascular invasion (MVI) is a valuable predictor of survival in hepatocellular carcinoma (HCC) patients. This study developed predictive models using eXtreme Gradient Boosting (XGBoost) and deep learning based on CT images to predict MVI preoperatively., Methods: In total, 405 patients were included. A total of 7302 radiomic features and 17 radiological features were extracted by a radiomics feature extraction package and radiologists, respectively. We developed a XGBoost model based on radiomics features, radiological features and clinical variables and a three-dimensional convolutional neural network (3D-CNN) to predict MVI status. Next, we compared the efficacy of the two models., Results: Of the 405 patients, 220 (54.3%) were MVI positive, and 185 (45.7%) were MVI negative. The areas under the receiver operating characteristic curves (AUROCs) of the Radiomics-Radiological-Clinical (RRC) Model and 3D-CNN Model in the training set were 0.952 (95% confidence interval (CI) 0.923-0.973) and 0.980 (95% CI 0.959-0.993), respectively (p = 0.14). The AUROCs of the RRC Model and 3D-CNN Model in the validation set were 0.887 (95% CI 0.797-0.947) and 0.906 (95% CI 0.821-0.960), respectively (p = 0.83). Based on the MVI status predicted by the RRC and 3D-CNN Models, the mean recurrence-free survival (RFS) was significantly better in the predicted MVI-negative group than that in the predicted MVI-positive group (RRC Model: 69.95 vs. 24.80 months, p < 0.001; 3D-CNN Model: 64.06 vs. 31.05 months, p = 0.027)., Conclusion: The RRC Model and 3D-CNN models showed considerable efficacy in identifying MVI preoperatively. These machine learning models may facilitate decision-making in HCC treatment but requires further validation.

Objective: To evaluate the roles between two different HIV self-testing models in promoting HIV-testing among men who have sex with men (MSM). Methods: This paper focuses on two HIV self-testing service models. The first; is the online self-testing model (HIV self-testing conventional model) with the sexual health promotion network platform. The other one is an innovative HIV self-testing model (secondary distribution model), based on the previous program. The two different self-testing models, including the number of indexes and alters, the positive rate, and the demographics of indexes and alters, are compared. The influence of volunteers with or without leadership on the number of HIV self-test kits distributed or self-use is analyzed through the leadership survey scale. Results: The return rates of HIV self-testing results in the two models are 94.7%(323/341) and 99.2%(1 141/1 150), respectively, within 30 days. The proportion of alters in the secondary distribution is significantly higher (45.9%,281/612) than the conventional HIV self-testing (6.3%,20/318). In the secondary distribution model, the difference between the number of indexes and alters indicators including age, marital status, residence, sex orientation, anal sex with men in the past six months, and HIV test are statistically significant ( χ 2 test, all P <0.05). The opinion leader of MSM has significantly impacted the promotion of HIV self-testing ( P <0.05). Conclusions: Both models can promote HIV self-testing, result return, and HIV positive detection among MSM. In terms of expanding the testing and detection of HIV positive, the secondary distribution mode shows more obvious advantages, which significantly promotes a large number of MSM who have never been tested for HIV to undergo HIV testing. Influential indexes have a significant effect on increasing the HIV testing rate and promoting HIV testing among MSM.

Objective: To evaluate the effectiveness of HIV/syphilis joint self-testing in promoting syphilis testing among men who have sex with men (MSM). Methods: In July 2019, the research participants were recruited through the Danlan website (https://www.danlan.org). Participants who met the selection criteria, and were randomly assigned into one of the three study groups (1∶1∶1) including HIV/syphilis joint self-testing group and lottery incentive self-testing group and control group. Self-test reagents were mailed to HIV/syphilis joint self-testing group and lottery incentive self-testing group, and the subjects in control group were encouraged to go to offline locations for testing. One month later, follow-up was conducted to evaluate the differences in the testing rates of syphilis among the three groups. Results: A total of 145 subjects were included in this study, including 48 in control group, 49 in HIV/syphilis joint self-testing group and 48 in lottery incentive self-testing group. During the follow-up period, the self-testing rate of syphilis was 74.4% (32/43) in HIV/syphilis joint self-testing group, 70.0% (28/40) in lottery incentive self-testing group and 36.4% (16/44) in control group. Multivariate logistic analysis revealed that the proportions of syphilis testing in HIV/syphilis joint self-testing group and lottery incentive self-testing group were 5.38 (95% CI : 2.06-14.04) times and 4.54 (95% CI : 1.75-11.74) times higher than that in control group during the follow-up period. Conclusions: HIV/syphilis joint self-testing and lottery-incentives-prompted self-testing significantly increased the testing rate of syphilis in MSM, respectively. HIV/syphilis joint self-testing is feasible for promotion.

The current situation of AIDS prevention and control is still challenging in China. Although China has made great progress in expanding HIV testing and promoting case identification, there are still a large number of HIV-infected individuals who have not been identified, which might influence the overall achievement of the goal of HIV/AIDS prevention and control. Thus, China needs to further promote self-testing while conducting routine HIV testing and use it as a supplement to further expand HIV testing coverage. The articles in this issue focus on the global situation of HIV self-testing services, reports the changes of self-testing among MSM in China from 2013 to 2018, and compares the effects of different HIV/syphilis self-testing models in promoting HIV/syphilis testing in key populations in order to achieve the overall goal of AIDS prevention and control in China.

HIV self-testing is a key measure and strategy to expand the coverage of HIV testing in key populations, which has great value in application and high acceptance in key populations. The World Health Organization (WHO) issued the Guidelines on HIV self-testing and partner notification in 2016 to support the application of HIV self-testing and provide specific guidance for countries and organizations to develop corresponding public health policies for the purpose of improving the accessibility and utilization of HIV diagnostics. HIV self-testing has been promoted in many countries and has achieved great results. This article provides an overview of the current domestic and international HIV self-testing policies, intervention models, the use of self-testing kits, the accuracy of self-testing kits, and the application of pre- and post-testing counseling services to provide reference for the further improvement of HIV self-testing in China.

Objective: To understand the changing trends of HIV testing rates, with a focus on HIV self-testing, and to evaluate the impact of HIV self-testing on expanding HIV testing among MSM in China in past few years. Methods: MSM were recruited online nationwide via a gay social networking app (Blued) from 2013 to 2016 and 2018. The survey collected information about socio-demographic backgrounds, sexual behaviors, and prior HIV testing experiences, including HIV self-testing. Trend analyses were conducted. Results: Respectively, 1 342, 1 424, 1 173, 2 105 and 699 MSM were recruited nationwide from 2013 to 2016, and in 2018. The mean age was (30.6±6.6)years in 2013 and showed a decreasing trend afterwards. The HIV testing rate was 60.0% (805/1 342) in 2013 and there was a rising trend from 2013 to 2016, and 2018 (trend Z =19.3, P <0.001), reaching a peak at 77.3% (540/699) in 2018. Further, the HIV self-testing rate increased from 19.3% (259/1 342) in 2013 to 58.1% (406/699) in 2018 ( χ 2 =237.5, P <0.001). The proportion of MSM who had HIV self-testing among prior HIV testers significantly increased from 32.2% (259/805) to 75.2% (406/540) during the study period (trend Z =14.3, P <0.001). Conclusions: The HIV testing rate, HIV self-testing rate and proportion of men who had HIV self-testing among former HIV testers among web-based Chinese MSM showed substantial increases from 2013 to 2016,and 2018. This suggests that HIV self-testing may have a significant effect on the expansion of HIV testing coverage in MSM, and has important public health implications for HIV/AIDS prevention in China.

Few studies in China focused on serotypes of Streptococcus pneumoniae in patients with invasive pneumococcal disease (IPD). We aimed at investigating the serotype distribution for IPD-causing S. pneumoniae and vaccine coverage among Chinese children and adults. This was a multicenter, observational study to collect S. pneumoniae isolates from normal sterile sites and IPD-related clinical information among children and adults. Serotyping was performed by a Capsule-Quellung reaction test using type-specific antisera. The study collected a total of 300 eligible isolates (pediatric = 148, adult = 152) were serotyped in a central laboratory. The most prevalent serotypes were 19A (20.9%) and 23 F (20.3%) in the pediatric group; 3 (21.7%) and 19 F (11.8%) in the adult group. PCV10 had low-to-moderate serotype coverage rates for children (60.8%) and adults (34.2%). PCV13 and PPV23 had high coverage rates for children (89.9%, 93.2%) and adults (70.4%, 82.9%), respectively, Investigational PCVs including PCV15 and PCV20 had high estimated coverage rates in children (89.9%, 93.9%). The study identified 269 subjects with IPD reported as the primary diagnosis in the medical records. Sepsis (48/136, 35.3%) and pneumonia (48/133, 36.1%) had the highest occurrence in the pediatric and adult groups, respectively. Study findings showed that non-PCV7  S. pneumoniae 19A and 3 were the most prevalent serotypes in Chinese children and adults, respectively. High-valent vaccines had similar coverage rates and may have a greater potential in preventing IPD.

Background: Human immunodeficiency virus (HIV) self-testing may help improve test uptake among female sex workers. China has implemented many HIV self-testing programs among men who have sex with men, creating an opportunity for promotion among female sex workers. However, there is a limited literature on examining HIV self-testing among female sex workers. This study aimed to examine HIV self-testing experiences and its determinants among female sex workers in China., Methods: A venue-based, cross-sectional study was conducted among Chinese female sex workers in 2019. Participants completed a survey including social-demographic characteristics, sexual behaviors, and HIV self-testing history, the distribution of which were analyzed using descriptive analysis. Multivariable logistic regression was conducted to identify associations with HIV self-testing., Results: Among 1287 Chinese female sex workers, 1072 (83.3%, 95% confidence interval [CI] 81.2-85.3%) had ever tested for HIV, and 103 (8.0%, 95% CI 6.6-9.6%) had ever used HIV self-testing. More than half reported that the self-test was their first HIV test (59.2%, 61/103), around one-fifth reported HIV self-testing results influenced the price of sex (21.4%, 22/103). A minority of individuals reported ever experiencing pressure to undertake HIV self-testing (6.8%, 7/103). After adjusting for covariates, HIV self-testing was positively associated with receiving anal sex in the past month (adjusted odds ratio [aOR] = 2.2, 95% CI 1.4-3.5), using drugs before or during sex (aOR = 2.8, 95% CI 1.8-4.5), injecting drugs in the past 6 months (aOR = 2.6, 95% CI 1.2-6.0), being diagnosed with other sexually transmitted infections (aOR = 1.6, 95% CI 1.0-2.5), tested for other sexually transmitted infections in the past six months (aOR = 3.4, 95% CI 2.1-5.5), ever tested in the hospital (aOR = 3.4, 95% CI 2.0-5.6), and ever tested in the community (aOR = 1.5, 95% CI 1.2-1.9)., Conclusions: Our findings suggest that HIV self-testing could expand overall HIV testing uptake, increase HIV testing frequency, reach sub-groups of high-risk female sex workers and has limited potential harms among female sex workers. HIV self-testing should be incorporated among Chinese female sex workers as a complement to facility-based HIV testing services.

Microsatellite instability (MSI) has been approved as a pan-cancer biomarker for immune checkpoint blockade (ICB) therapy. However, current MSI identification methods are not available for all patients. We proposed an ensemble multiple instance deep learning model to predict microsatellite status based on histopathology images, and interpreted the pathomics-based model with multi-omics correlation. Methods: Two cohorts of patients were collected, including 429 from The Cancer Genome Atlas (TCGA-COAD) and 785 from an Asian colorectal cancer (CRC) cohort (Asian-CRC). We established the pathomics model, named Ensembled Patch Likelihood Aggregation (EPLA), based on two consecutive stages: patch-level prediction and WSI-level prediction. The initial model was developed and validated in TCGA-COAD, and then generalized in Asian-CRC through transfer learning. The pathological signatures extracted from the model were analyzed with genomic and transcriptomic profiles for model interpretation. Results: The EPLA model achieved an area-under-the-curve (AUC) of 0.8848 (95% CI: 0.8185-0.9512) in the TCGA-COAD test set and an AUC of 0.8504 (95% CI: 0.7591-0.9323) in the external validation set Asian-CRC after transfer learning. Notably, EPLA captured the relationship between pathological phenotype of poor differentiation and MSI ( P < 0.001). Furthermore, the five pathological imaging signatures identified from the EPLA model were associated with mutation burden and DNA damage repair related genotype in the genomic profiles, and antitumor immunity activated pathway in the transcriptomic profiles. Conclusions: Our pathomics-based deep learning model can effectively predict MSI from histopathology images and is transferable to a new patient cohort. The interpretability of our model by association with pathological, genomic and transcriptomic phenotypes lays the foundation for prospective clinical trials of the application of this artificial intelligence (AI) platform in ICB therapy., Competing Interests: Competing Interests: F.Y., Y.Z., W.J.L., T.X.W., W.J.H., W.M.T and J.H.Y. are employed by Tencent and W.J.C. is employed by Shanghai Tongshu Biotechnology Co., Ltd., (© The author(s).)

Few-layered molybdenum disulfide (MoS 2 ) has demonstrated promising advantages for the integration of next-generation electronic devices. A vertical short-channel MoS 2 transistor with a channel length of sub-10 nm can be realized using mica as the insulated mesa and MoS 2 flake dry-transferred onto the mica as the channel. A near-perfect symmetrical and fully saturated output characteristic can be obtained for the positive or negative drain-source voltage. This result is attributed to an effective transformation of the drain-source electrode contact from Schottky contact to Ohmic contact via forming gas annealing. The vertical-channel MoS 2 transistor with a channel length of 8.7 nm exhibits excellent electrical characteristics, for example, a negligible hysteresis voltage of 60 mV, an extraordinarily small subthreshold swing of 73 mV/dec, a considerably weakened drain-induced barrier-lowering effect (100 mV/V), and the first-reported intrinsic delay time of 2.85 ps. Moreover, a logic inverter can be realized using the two vertical-channel MoS 2 transistors, with a high voltage gain of 33. Experimental results indicate that the developed method is a potential approach for fabricating MoS 2 transistors with an ultrashort channel and high performance, and consequently, manufacturing MoS 2 -based integrated circuits.