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Extracting k-order maximal-sum principal submatrix from an n-order real matrix is a typical combinatorial optimization problem and an NP-hard problem. To improve the computational efficiency of solving this problem, we, in this paper, propose an accelerated algorithm with row-by-row updates, called the fusion row update accelerated algorithm, which works by reducing the number of addition operations for submatrix elements. The new algorithm is applied to accelerate color combination selection and maximize color difference, which improves the readability of data visualization results; it is also applied to accelerate stock investment portfolio selection and minimize correlation degree, which decreases the investment risk in the view of daily return volatility.

BackgroundPretreatment drug resistance (PDR) can limit the effectiveness of HIV antiretroviral therapy (ART). The aim of this study was to assess the prevalence of PDR among HIV-positive individuals that initiated antiretroviral therapy in 2014–2020 in southwestern China.MethodsConsecutive cross-sectional surveys were conducted in Qinzhou, Guangxi. We obtained blood samples from individuals who were newly diagnosed with HIV in 2014–2020. PDR and genetic networks analyses were performed by HIV-1 pol sequences using the Stanford HIV-database algorithm and HIV-TRACE, respectively. Univariate and multivariate logistic regression models were used to explore the potential factors associated with PDR.ResultsIn total, 3236 eligible HIV-positive individuals were included. The overall prevalence of PDR was 6.0% (194/3236). The PDR frequency to NNRTI (3.3%) was much higher than that of NRTI (1.7%, p ConclusionsThe overall prevalence of PDR was medium, numerous cases of the same DRMs among genetically linked individuals in networks further illustrated the importance of surveillance studies for mitigating PDR.

BACKGROUND Nearly one-third of new HIV infections occurred among youth in 2019 worldwide. Previous studies suggested that student youths living with HIV and nonstudent youths living with HIV might differ in some risk factors, transmission routes, HIV care, and disease outcomes. OBJECTIVE This study aimed to compare the HIV epidemic, disease outcomes, and access to care among student and nonstudent youths living with HIV aged 16 to 25 years in Guangxi, China. METHODS We performed a historical cohort study by extracting data on all HIV or AIDS cases aged 16 to 25 years in Guangxi, China, during 1996-2019 from the Chinese Comprehensive Response Information Management System of HIV or AIDS. We conducted analyses to assess possible differences in demographic and behavioral characteristics, HIV care, and disease outcomes between student and nonstudent youths living with HIV. Multivariate Cox regression was used to assess differences in mortality and virologic failure between student and nonstudent cases. RESULTS A total of 13,839 youths aged 16 to 25 years were infected with HIV during 1996-2019. Among them, 10,202 cases were infected through sexual contact, most of whom were men (n=5507, 54%); 868 (8.5%) were students, and 9334 (91.5%) were not students. The number of student youths living with HIV was lower before 2006 but gradually increased from 2007 to 2019. In contrast, the nonstudent cases increased rapidly in 2005, then gradually declined after 2012. Student cases were mainly infected through homosexual contact (n=614, 70.7% vs n=1447, 15.5%; PPPPP=.008). The virologic failure rate was 2.3 and 2.6 per 100 person-years among student and nonstudent youths living with HIV, respectively. Nonstudent cases had double the risk of virologic failure compared to student cases (AHR 1.9, 95% CI 1.3-2.6; P CONCLUSIONS Nonstudent youths living with HIV might face a low CD4 count at the time of HIV diagnosis, delayed ART initiation, and increased risk of death and virologic failure. Thus, HIV prevention and interventions should target youths who dropped out of school early to encourage safe sex and HIV screening, remove barriers to HIV care, and promote early ART initiation to curb the HIV epidemic among youths.

Background Pretreatment drug resistance (PDR) can limit the effectiveness of HIV antiretroviral therapy (ART). The aim of this study was to assess the prevalence of PDR among HIV-infected individuals that initiated antiretroviral therapy in 2014–2020 in southwestern China. Methods Consecutive cross-sectional surveys were conducted in Qinzhou, Guangxi. We obtained blood samples from individuals who were newly diagnosed with HIV in 2014–2020. PDR and genetic networks analyses were performed by HIV-1 pol sequences by using the Stanford HIV-database algorithm and HIV-TRACE, respectively. Univariate and multivariate logistic regression models were used to explore the potential factors associated with PDR. Results In total, 3236 eligible patients were included. The overall prevalence of PDR was 6.0% (194/3236). The PDR frequency to NNRTI (3.3%) was much higher than that to NRTI (1.7%) and PI (1.2%) (p

The aim of this review is to describe long-term HIV epidemiology and prevention trends in Guangxi, a provincial-level region located along a major drug trafficking corridor in southwestern China. Between 1996 and 2006, HIV transmission in Guangxi was primarily fueled by Injection Drug Use (IDU). Since 2006, heterosexual sex has become the dominant mode of HIV transmission, followed by drug injection. Moreover, older, heterosexual adults appear to be at increased risk for HIV. The vast majority of new HIV cases are attributed to local HIV subtypes already circulating within Guangxi (93%), though imported subtypes are associated with younger age groups. Since 2011, HIV incidence in Guangxi has stabilized, due in part to HIV prevention efforts that include expanded HIV testing, antiretroviral treatment, and other intervention measures. Between 1996 and 2017, Guangxi, China experienced dramatic changes in the primary HIV transmission mode and at-risk age group. Due in part to local and National AIDS control and prevention campaigns, HIV incidence trends in Guangxi no longer appear to be increasing.

To improve the sparseness of the base matrix in incremental non-negative matrix factorization, we in this paper present a new method, orthogonal incremental non-negative matrix factorization algorithm (OINMF), which combines the orthogonality constraint with incremental learning. OINMF adopts batch update in the process of incremental learning, and its iterative formulae are obtained using the gradient on the Stiefel manifold. The experiments on image classification show that the proposed method achieves much better sparseness and orthogonality, while retaining time efficiency of incremental learning.

Background: Some cases retested positive for SARS-CoV-2 following negative testing results and discharge, which attracted widespread concern. However, the potential risk factors associated with re-detectable positive tests in a large sample of cases who recovered from COVID-19 has not been well estimated. Methods: A total of 745 discharged COVID-19 cases were enrolled between 30 January and 9 September 2020 in Guangzhou, China. Data on the clinical characteristics, comorbidities, drug therapy, RT-PCR testing, and contact modes to close contacts were collected. Re-positive cases were confirmed by guidelines issued by China. The re-positive rate of in different settings was calculated. Univariable and multivariable logistic regression models were used to explore the potential risk factors associated with COVID-19 re-positivity. Findings: Among 745 discharged cases, 157 (21.1%; 95%CI, 18.2% to 24.0%) were retested positive with 55 (35.0%) of asymptomatic, 15 (9.6%) of mild, 83 (52.9%) of moderate and 4 (2.6%) of severe at the first admission. The median time from discharge to re-positivity was 8.0 days (IQR, 8.0 to 14.0 days). Most re-positive cases were without clinical symptoms and lymphocyte cell counts increased than before. The likelihood of re-positive testing for SARS-CoV-2 RNA was significantly higher among cases with younger age (OR, 3.88; 95%CI, 1.74 to 8.66, 0 to 17 years old), asymptomatic severity (OR, 4.36; 95%CI, 1.47 to 12.95) and without clinical symptoms (OR, 1.89; 95%CI, 1.32 to 2.70, without fever). Interpretation: We found that the re-positive rate of COVID-19 was relatively high, and they were re-tested positive with median days 8.0 to 14.0 post-discharge. Re-positive results were mainly observed in young cases without severe clinical symptoms. These findings suggest that a significant proportion of cases could carry virus fragments for a long time, and effective management, such as prolonged quarantine phase of discharged cases, is necessary. Funding Statement: The Guangdong Province Universities and Colleges Pearl River Scholar Funded Scheme; the Construction of High-level University of Guangdong; Young Elite Scientists Sponsorship Program by CAST; the National Natural Science Foundation of China; the Zhejiang University special scientific research fund for COVID-19 prevention and control. Declaration of Interests: We declare no competing interests. Ethics Approval Statement: This study was reviewed and approved by the Ethics Committee of GZCDC. As required by the National Health Commission of China, CDCs were responsible for the work for an ongoing public health response to COVID-19, and our cohort study was based on the data by GZCDC. Patients were informed about the surveillance before providing written consent, and data were collected and anonymized for analysis. All analysis of personally identifiable data took place onsite at the GZCDC.

Background: WHO has recommended that antiretroviral therapy be provided to all HIV patients to reduce future HIV transmission at the population level. Aside from the HPTN 071 (PopART) community based randomized trial which indicated that universal testing and treatment can reduce HIV incidence at the population level, such a public health strategy has not previously been studied in real-world settings. Methods: In this longitudinal phylogenetic-network study in Guangxi, China, the longitudinal baseline and follow-up data was collected from HIV patients in 2014 and newly diagnosed HIV patients from 2015 to 2018, respectively. We used a genetic distance threshold of 0.75% to analyze the proportions of genetic linkage between annual newly diagnosed HIV patients with HIV patients at baseline stratified by treatment. Findings: Among 804 newly diagnosed HIV patients during 2015-2018, 399 (49.6%) of them genetically linked to HIV patients at baseline during 2014-2017. The overall proportion of genetic linkage between newly diagnosed HIV patients during 2015-2018 with untreated and treated HIV patients at baseline during 2014-2017 was 6.2% and 2.9%, respectively. The prevention efficacy in HIV transmission for treated HIV patients was 53.5% (95% CI: 42.0%-65.0%). There was no significant reduction in HIV transmission among treated HIV patients on dropout or with missing viral load measures. Interpretation: Combined with the HPTN 071 (PopART) study, our study results strongly support the feasibility of treating all HIV patients for future reductions in HIV transmission at the population level in real-world settings. Comprehensive intervention prevention programs are urgently needed. Funding Statement: This study was supported by the Guangxi Science and Technology Bureau (Grant AB16380213), Guangxi Medical and Health Project (Z20170126), National Natural Science Foundation of China (Grants 11971479, 81460510 and 81360442), Guangxi Bagui Honor Scholarship, Ministry of Science and Technology of China (2018ZX10721102-006, 2018ZX10715008), and Chinese State Key Laboratory of Infectious Disease Prevention and Control. Declaration of Interests: The authors declare that they have no conflicts of interest. Ethics Approval Statement: The institutional review board (IRB) of the Guangxi CDC approved this study.

ObjectivesChina has continued to expand antiretroviral therapy (ART) services and optimise ART guidelines in an effort to significantly reduce and prevent mortality and transmission rates among HIV patients. However, no study to date has compared treatment outcomes of initial differential antiretroviral regimens among HIV patients in a real-world setting in China. This study aimed to compare the effects of different ART regimens on treatment outcomes among adults.DesignObservational retrospective cohort study.SettingData from 2011 to 2013 in Guangxi, China.ParticipantsPatients aged ≥18 years (n=25 732) were selected.ResultsA total of 25 732 patients were included in this study. The average mortality and attrition rate were 2.64 and 4.98, respectively, per 100 person-years. Using Cox proportional hazard models, zidovudine-based (AZT-based) regimen versus stavudine-based (D4T-based) regimen had an adjusted HR (AHR) for death of 0.65 (95% CI 0.58 to 0.73); the AHR of tenofovir-based (TDF-based) versus D4T-based regimens was 0.81 (95% CI 0.71 to 0.92), and of lopinavir–ritonavir-based (LPV/r-based) versus D4T-based regimens, 1.19 (95% CI 1.04 to 1.37). AZT-based versus D4T-based regimens had an AHR for dropout of 0.89 (95% CI 0.81 to 0.97); this ratio for TDF-based versus D4T-based regimens was 0.88 (95% CI 0.80 to 0.98), and for LPV/r-based versus D4T-based regimens, 1.42 (95% CI 1.27 to 1.58). AZT-based and TDF-based regimens had a lower risk compared with D4T-based regimens, while LPV/r-based regimens had a higher risk. High gastrointestinal reactions and poor adherence were observed among HIV patients whose initial ART regimen was LPV/r-based.ConclusionsOur study found that the treatment outcomes of initial ART regimens that were AZT-based or TDF-based were significantly better than D4T-based or LPV/r-based regimens. This finding could be related to the higher rates of gastrointestinal reactions and poorer adherence associated with the LPV/r-based regimens compared with other initial ART regimens.

Coclustering approaches for grouping data points and features have recently been receiving extensive attention. In this paper, we propose a constrained dual graph regularized orthogonal nonnegative matrix trifactorization (CDONMTF) algorithm to solve the coclustering problems. The new method improves the clustering performance obviously by employing hard constraints to retain the priori label information of samples, establishing two nearest neighbor graphs to encode the geometric structure of data manifold and feature manifold, and combining with biorthogonal constraints as well. In addition, we have also derived the iterative optimization scheme of CDONMTF and proved its convergence. Clustering experiments on 5 UCI machine-learning data sets and 7 image benchmark data sets show that the achievement of the proposed algorithm is superior to that of some existing clustering algorithms.

Non-negative matrix factorization (NMF) becomes an important dimension reduction and feature extraction tool in the fields of scientific computing and computer vision. In this paper, for using the known label information in the original data, we put forward a semi-supervised NMF algorithm called constrained dual graph regularized non-negative matrix factorization (CDNMF). The new algorithm employs hard constraints to retain the priori label information of samples, constructs two association graphs to encode the geometric structures of the data manifold and the feature manifold, and incorporates the additional bi-orthogonal constraints to improve the identification ability of data in the new representation space. We have also developed an iterative optimization strategy for CDNMF and proved its convergence. Finally the clustering experiments on five standard image data sets show the effectiveness of the proposed algorithm.

This study aimed to identify the association of unsafe sex behaviors with HIV infection among the male clients who purchase commercial sex in low-cost sex venues. A cross-sectional study was conduct in a southern province of China among male, low-cost commercial sex clients, who were over 50 years old. Participants were interviewed using a structured questionnaire and had completed HIV testing. Among the 3,485 participants, the prevalence of HIV was 2.96% (95% confidence interval: 2.40–3.52%). The associated risk factors studied for HIV infection included (1) not currently married; (2) use of counterfeit TCMs with sildenafil; (3) noncondom use during commercial purchased sex; and (4) recent engagement of commercial sex within past week. Given the high prevalence of HIV infection among the study group, more political policy intervention and health education should be considered for the identified subpopulation (over 50-year-old men in low-cost commercial venues, counterfeit TCMs with sildenafil and...

Domestic garbage classification is required in many cities, however, optimal transportation of classified garbage has not been widely studied. Here, the optimal transportation of the classified domestic garbage from the waste transfer center to the garbage disposal station is considered. The locations of waste transfer centers, map distances between these waste transfer centers, different types of garbage disposal stations and the quantity of waste in different areas are used as key factors for constructing a weighted graph model. This study considers Nanshan District in Shenzhen, China as a case study. Solutions were obtained by applying the proposed model to the area using data from 2011. To achieve the decision goal of identifying feasible traveling distance and time for each trash truck, the number of routes considered for recyclable waste transportation was no less than 5; for non-recyclable waste transportation was no less than 2; and for harmful waste transportation was 4. The study provides an auxiliary management tool for optimal municipal solid waste disposal that improves the sustainability of the system.

Background: China has ambitious to achieve significant reductions in HIV transmission and HIV-related mortality by adopting the World Health Organization's “Treat All” approach. Such a prevention strategy is needed future study on regional scale. Methods: An observational cohort study of HIV epidemiology and treatment databases was used to study the effectiveness of antiretroviral therapy on the transmission of HIV in serodiscordant couples in Guangxi of China. Results: A total of 7713 couples were entered into the cohort study analysis which included 1885 couples in the treatment-naive cohort and 5828 couples in the treated cohort. During the follow-up of 18985.29 person-years from 2003 to 2014, the average incidence of HIV was 2.4 per 100 person-years (95% CI 2.1–2.6). HIV seroincidence rate was significantly higher among the treatment naive group (4.2 per 100 person-years, 3.7–4.8) compared with the on treatment group (1.6 per 100 person-years, 1.3–1.8). An overall 45% reduction in risk of HIV transmission among serodiscordant couple was associated with ART treatment (adjusted Hazard Ratio [HR] 0.55, 95% Confidence Interval [CI] 0.44–0.69). Treatment prevention had significantly effectiveness for most baseline characteristics of index partners, such as for male, female, age above 25 years, education below high school, farmer, infected by heterosexual intercourse. Conclusion: Treatment-as-prevention can be implemented in the real-world on a national or regional scale, but ART adherence and comprehensive harm reduction while implementing this strategy require further study. Keywords: HIV, ART, Sero-discordant couples, Transmission, Cohort study

This paper proposes a universal framework for image change detection for daily basic use. Overall, the challenge lies on the interference factors such as noise captured during shooting, illumination variation in time-series images and rotation angle of the view. To overcome these problems, we introduce the Comprehensive Preprocessing and Spectral Log-Demons Algorithm (CPP-SLD). We begin our methodology with Comprehensive Preprocessing methods, aiming to eliminate the irrelevant factors. We analyze the sparseness property of gradient distribution to correct the bias. In addition, we make use of the symmetric distribution of the radial gradient to correct the vignetting. Besides, Wiener filtering and Gaussian filtering are both used to denoise and smooth the images. Finally, the Spectral Log-Demons algorithm is applied to register. Then by subtraction we detect the change. Our framework can achieve a widespread success under different circumstances. Moreover, we compare our method with 3 ohthers, and by qualitative and quantitative analysis we expound the validity and robustness of our method.

To understand the demographic characteristics of the HIV positive cases detected in the screening project in communicable disease prevention demonstration area in Guangxi Zhuang autonomous region and analyses the related factors of HIV infection.HIV antibody detection was conducted for local people aged no less than 15 years old in 3 demonstration counties, and the demographic information of the subjects were collected. The factors influencing HIV infection were analyzed with software PASW Statistics 18.0.A total of 770 454 local people aged over 15 years were screened, the HIV infection rate was 1.58‰ among them. The positive cases were mainly married males aged≥30 years and with the educational level of primary school and junior middle school. Thus male, age over 30 years and educational level of primary school and junior middle school. were the common risk factors for HIV infection, whereas being married was a protective factor for HIV infection in 3 demonstration counties, but Han ethnic group and divorced/widowed were risk factors for HIV infection in the demonstration county A, non-farmer, divorced/widowed and educational level of senior middle school were the risk factors for HIV infection in demonstration county B and Han ethnic group and farmer were risk factors HIV infection in demonstration county C.It suggested to conduct targeted HIV infection screening according to the survey results to find out the HIV cases in general population.

To analyze the cost effectiveness of HIV screening project in three Guangxi infectious disease special demonstration project countries in 2013.To calculate the funds used for the HIV screening project and to study the data on HIV/AIDS and HAART. A five-tree markov model was used to evaluate the quality adjusted life year (QALY) of this HIV screening project and to analyze the related cost effectiveness of the project.The cost of HIV screening in Guangxi infectious disease special demonstration project areas was 19.205 million Yuan and having identified 1 218 HIV/AIDS patients. The average costs for HIV/AIDS positive detection in three project countries were 14.562, 18.424 and 14.042 thousand Yuan per case. The QALYs gained from finding a HIV/AIDS case were 12.736, 8.523 and 8.321 on average, with the total number of QALYs gained from the project as 5 973.184, 3 613.752 and 2 704.325. The overall cost effectiveness ratio of the project was 1.562 thousand Yuan per QALY, and 1.143, 2.162 and 1.688 thousand Yuan per QALY in these three project countries. Project country "A" showed better cost effectiveness index than country B and C.The HIV screening project in Guangxi seemed relatively cost-effective but the average cost of HIV/AIDS positive detection was expensive. To strengthen HAART work for HIV/AIDS could improve the cost-effective of the project.

To understand the current situation and characteristics of commercial sexual behavior among old male clients in Guangxi, and to explore the associated risk factors of HIV infection.The areas in Guangxi where more old male HIV cases were reported followed by survey on those male clients who were over 60 years of age, were selected. A total of 5 ml blood sample was collected to test antibodies of HIV and syphilis. Risk factors were calculated by the multivariate logistic analysis method.A total of 1 236 questionnaires were completed in the survey. 65.61% of the old male clients were from low-grade venues with 53.64% of them never using a condom when engaging in commercial sex behavior. 47.33% of them patronized sex workers for around 10 years. 53.32% of them patronized prostitutes not less than 2 times in the last 30 days. Thirty subjects were HIV positive (2.43%) and 40 were syphilis positive (3.24%). Factor as 'having fixed partners' (OR = 0.302, 95% CI:0.140-0.650) appeared protective for the old male clients of HIV infection, with a history of patronizing sex workers from 1 to 5 years (OR = 2.552, 95% CI: 1.086-5.998). Frequency of patronizing sex workers not less than 4 times in the last 30 days (OR = 3.002, 95%CI:1.047-8.607) seemed the high risk factor of HIV infection.Older-aged male clients showed high HIV and syphilis infection rates in Guangxi, and most of them were using the low-grade venues. Commercial sexual behaviors in the areas would include early and, frequent exposure, but with poor protections. High risk factors of HIV infection might relate to "no fixed sexual partners" and "frequently commercial sexual behavior".

To understand the illegal sidenafil use among middle-aged and elderly male clients of female sex workers (FSWs) in central region of Guangxi as well as on related risk factors. Initial evaluation regarding the effect of illegal sidenafil use on HIV infection among the middle-aged and elderly men was also conducted.A survey was conducted among the over 50-year-olds male clients of low-grade prostitutions in central areas of Guangxi. Information on demographics, related behavior, and illegal sidenafil use was collected. 5 ml blood sample were taken to test antibodies of HIV and syphilis. PASW Statistics 18.0 was used for data analysis.2 056 questionnaires were completed. 23.1% of the participants said they had ever used illegal sidenafil. The risk of sildenafil use was low among the male clients who were not over 60 years old (OR = 0.586, 95% CI:0.459-0.749). The risks of sildenafil use among the male clients with frequencies(in the past 30 days) of having commercial sex behavior were:only once (OR = 0.184, 95%CI:0.090- 0.378), twice (OR = 0.187, 95%CI:0.089-0.378) or three times (OR = 0.181, 95%CI: 0.085-0.384) lower than those with more than five times. Being single (OR = 0.608, 95% CI: 0.396-0.933), married/cohabiting (OR = 0.533, 95% CI:0.391-0.727), having unstable partners (OR = 0.558, 95%CI:0.393-0.792) seemed to be protective on those who used sildenafil, among the study population. Factors as 'never use the condom (OR = 1.642, 95%CI:1.125-2.397) or 'seldom use as condom (OR = 1.840, 95%CI:1.278-2.648) when having commercial sex, were under high risk among the sildenafil users. Forty-seven subjects were HIV positive, with the prevalence as 2.29% in this study population. Male clients of the FSWs who used sidenafil were under 60 years of age and with higher risk of HIV infection.people who were ≥60 years old, divorced/widowed/ separated, with frequencies (in the past 30 days) of having commercial sex more than 5 times, never or occasionally using a condom when having commercial sex etc., appeared at high risk. Middle-aged and elderly male clients who used sildenafil or sildenafil-like drugs were under high risk of contracting HIV infection.

To explore demographics, clinical and medication profiles, patients’ social support, and perceived health status in HIV/TB coinfected patients in Guangxi, China. We performed a cross-sectional study in the HIV clinic of the Guigang City People's Hospital (N = 150). Health professionals conducted face-to-face interviews and collected data from patients’ electronic medical records regarding patients’ demographic, clinical, and medication information, as well as their social support and perceived health status. We classified all HIV/AIDS patients into HIV monoinfected and TB coinfected, at a ratio of 2:1. Compared with the HIV monoinfected, patients with HIV/TB coinfection were more likely to be older, male, less educated, unemployed, carrying health insurance, having advanced stage of HIV infection, longer history with HIV, and other opportunistic infections. Patients coinfected with TB were also more likely to hold a negative belief that their HIV treatment could prevent exacerbations, and reported significantly worse emotional/informational support, social interaction, and perceived health status. Better social support and better self-efficacy to the HIV treatment adherence was significantly associated with better perceived health status among patients with HIV and TB coinfection. Having HIV/TB coinfection was associated with poorer perceived general well-being and mental health, particularly in those undergoing TB therapy. Our findings suggest the need for mental health referrals and medication management for coinfected individuals, as well as further efforts and policies to improve coordinated care.