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A chiral Brønsted acid‐catalysed asymmetric hydrophosphinylation of 2‐vinylazaarenes by secondary phosphine oxides is described. A variety of P‐chiral 2‐azaaryl‐ethylphosphine oxides are synthesized with high yields and ees, of which both the substituents of phosphines and azaarenes can be flexibly modulated, underscoring an exceptionally broad scope of substrates. These adducts are valuable to asymmetric metal catalysis since the resultant P‐chiral tertiary phosphines from the reduction of them are verified as a kind of effective C1‐symmetric chiral 1,5‐hybrid P,N‐ligands. Importantly, this catalysis platform enables the generic and efficient kinetic resolution of P‐chiral secondary phosphine oxides. It thus provides an expedient approach to access the enantiomers of the P‐chiral tertiary phosphine oxides derived from asymmetric hydrophosphinylation, further improving the utility of the method. [ABSTRACT FROM AUTHOR]

A low‐power wideband self‐biased phase‐locked loop (SPLL) is proposed for multi‐protocol SerDes applications in this letter. With the proposed adaptive fast‐locking current circuit (AFLCC) and self‐biased charge pump (CP), the settling time is reduced significantly, and no extra power and jitter contribution. In addition, a start‐up module is adopted to reset the system to an optimal initial operating frequency quickly. The proposed 1‐3‐GHz SPLL, fabricated in TSMC 28‐nm CMOS process, occupies a compact 0.028 mm2 area. It achieves a roughly constant settling time of 5 μs over all frequencies and division ratios range. Only 0.96 mW is consumed at 1 GHz frequency. [ABSTRACT FROM AUTHOR]

Sexual transmission is currently the main mode of transmission of the human immunodeficiency virus (HIV). In this study, 181 HIV‐infected female cross‐border travelers entering Yunnan province were recruited between 2003 and 2012. HIV RNAs were extracted from their frozen serum and gag‐pol gene sequences were obtained for phylogenetic and recombination analyses. In total, 131 gag‐pol gene sequences were obtained successfully, at a rate of 72.4%. The most prevalent subtypes were CRF01_AE, followed by CRF08_BC, subtypes B and C. The other four subjects were classified as undefined subtypes and other recombinants. The subtype distribution of intravenous drug users was significantly different from that of sexually transmitted infections and unknown groups. The genetic distances of subtype B, C, and CRF01_AE strains were all close to the reference sequences from Yunnan province and Southeast Asian countries. Gene diversity and cocirculation of multiple subtypes were observed in female cross‐border travelers, and CRF01_AE was the dominant epidemic subtype. The advantages of these subtype preferences for sexual transmission were obvious in HIV infection and transmission among this population. Our findings also suggest that close attention should be given to the HIV infection status of the female migrant population. In addition, a description of their epidemic characteristics is significant for the surveillance and prevention of acquired immunodeficiency syndrome in the Yunnan province. [ABSTRACT FROM AUTHOR]

Human herpesviruses (HHVs) have a particularly high prevalence in certain high‐risk populations and cause increased morbidity and mortality in patients with acquired immunodeficiency syndrome (AIDS). Screening and treating subclinical HHV infections reduce human immunodeficiency virus (HIV) infection incidence, disease progression, and transmission. However, there are few studies on HHVs, HIV coinfection rates, and their related risk factors. We aimed to clarify the prevalence of all eight HHVs in peripheral blood samples collected from HIV‐positive patients, and explore the association of HHV infection in HIV‐positive patients in an HIV‐seropositive population in Yunnan. We recruited 121 HIV‐positive patients with highly active antiretroviral therapy (HAART) and 45 healthy individuals. All the eight HHVs were detected using polymerase chain reaction and their epidemiological information and clinical data were collected and statistically analyzed. A high prevalence of HHVs (89.3%) was observed in individuals with HIV infections and with herpes simplex virus (HSV)‐2 (65.3%), and HSV‐1 (59.5%) being the most common. Coinfection with more than two different HHVs was more common in patients with HIV infections receiving HAART (72.7%) than in healthy controls. Older age, being married, higher HIV‐1 plasma viral loads, and use of antiviral protease inhibitors were independently correlated with an increased frequency of HHVs, but we found no association with CD4 count, WHO HIV clinical stage, and HIV infection duration. Our findings are of great significance for the prevention of HHV opportunistic infection in patients with AIDS and their clinical treatment. Highlight: HHV co‐infection in AIDS patients deserves attention during the course of antiviral therapy. Suppressing HHV recurrences had a clinically significant effect on prolonging survival in some cohorts of HIV‐infected patients and may be an effective intervention in reducing HIV spread in China. [ABSTRACT FROM AUTHOR]

Xishuangbanna is a popular tourist destination in southern Yunnan Province, bordering with Vietnam and Laos, and Myanmar. There are more than 2 million cross-border travelers annually entering China at two land ports, Daluo and Mohan. To clarify the characteristics of HIV-1 prevalence among entry travelers, a retrospective epidemic investigation was conducted. Between 2003 and 2012, 196 among 91 432 entry travelers were detected to be HIV-1-positive, accounting for infection rate of 0.21%. Eighty-one gag-pol gene sequences were obtained for phylogenetic analyses and subsequent recombination analysis. It was shown that the most prevalent HIV-1 subtype in this population was circulating recombinant form (CRF) 01_AE (42, 51.86%), followed by CRF08_BC (17, 20.99%), CRF07_BC (4, 4.94%), B' (2, 2.47%), C (2, 2.47%), other recombinants (9, 11.11%), and undefined subtype (5, 6.17%). HIV-1 genotype distribution among travelers entering at two land ports is different, CRF01_AE and CRF08_BC accounted for a larger percentage among individuals from Daluo, whereas the proportions of subtype C and undefined URFs were larger among individuals from Mohan. The undefined subtype indicates the occurrence of novel HIV-1 subtype or CRF. This finding is useful for developing of AIDS prevention strategies. [ABSTRACT FROM AUTHOR]

From the intuition that natural face images lie on or near a low‐dimensional submanifold, the authors propose a novel spectral graph based dimensionality reduction method, named orthogonal enhanced linear discriminant analysis (OELDA), for face recognition. OELDA is based on enhanced LDA (ELDA), which takes into account both the discriminative structure and geometrical structure of the face space, and generates non‐orthogonal basis vectors. However, a significant fact is that eliminating the dependence of basis vectors can promote more effective recognition of unseen face images. For this purpose, the authors seek to improve the ELDA scheme by imposing orthogonal constraints on the basis vectors. Experimental results on real‐world face datasets show that, benefitting from orthogonality, OELDA has more locality preserving power and discriminative power than LDA and ELDA, and achieves the highest recognition rates among compared methods. [ABSTRACT FROM AUTHOR]

The prevalence and genotype distribution of human papillomavirus (HPV) vary throughout the world. To assess the prevalence and genotype distribution of HPV among three ethnic groups in two geographic locations in northwestern Yunnan, we recruited 522 women in Shangri-le (n=255) and Lijiang (n=267). PCR amplification of HPV DNA was performed on cervical cells from these women using two consensus primer systems (MY09/11 and GP5/ 6). Amplified-HPV DNA was genotyped using the HPV GenoArray test. Geographically, the HPV prevalence was significantly higher (P=0.002) among Shangri-le women than among Lijiang women. Infections with highrisk (HR)-HPV and with multiple HPV genotypes were also significantly more common (P=0.001) among women in Shangri-le than women in Lijiang. Additionally, the prevalence of overall, HR-HPV, and single genotype HPV infections was significantly higher (P=0.001) among Tibetan women than among Naxi and Han women. HPV-16 and HPV-33 were significantly more frequent in Shangri-le women compared with Lijiang (P=0.006) women. In addition, HPV-16 (9.81%) and HPV-33 (5.88%) were significantly more prevalent in Tibetan women than in Naxi and Han women. Here, for the first time, we highlight the significant variation in the prevalence and genotype distribution of HPV in various populations in the north-western region of Yunnan Province. [ABSTRACT FROM AUTHOR]

The aim of this study was to assess HIV-1 prevalence and the distribution of HIV-1 subtypes among travelers crossing the border at the HeKou land port. Between 2003 and 2012, 22,799 persons were randomly recruited from people entering China from Vietnam. In this crossing border population, a total of 161 (0.71%) travelers were determined as HIV-1-positive. From them, 140 HIV-1-positive serum samples were collected for RNA extraction and subsequent RT-nested PCR amplification of the group-specific antigen ( gag)-RT with a length of 2.6 kb. The DNA sequences were analyzed to determine the HIV-1 subtypes/recombinants. We found that the circulating recombinant form 01_AE (CRF01_AE) was the most common HIV-1 subtype, accounting for 49.4% (41/83) of the subtyped 83 samples, followed by CRF08_BC (26.5%, 22/83) and CRF07_BC (7.2%, 6/83). Only 1 sample was classified as subtype C. Thirteen cases could not be clustered into any known subtypes or CRFs and presented as unique recombinant forms (URFs). Of them, 6 recombination patterns were identified. They had distinct structures consisting of fragments of subtypes B, C, CRF01_AE, CRF07_BC and CRF08_BC. Between 2003 and 2012, CRF01_AE and CRE08_BC were shown to be the most prevalent recombinant forms identified each year. But yearly change of each subtype is uncertain regular among in these travelers during the past decade. Understanding the distribution of HIV-1 subtypes/recombinants and how it changes across time among individuals entering China from Vietnam through this land port is crucial to establish strategies for the prevention of HIV cross-border transmission. J. Med. Virol. 87:1500-1509, 2015. © 2015 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Hepatitis B virus (HBV) is one of the most prevalent pathogens in the world, and infection with this virus is a serious threat for public health. Yunnan is considered as an important endemic center for blood-borne viruses such as human immunodeficiency virus and hepatitis C virus, in China. However, the distribution and diversity of HBV subgenotypes remain unclear in Yunnan province. In the current study, HBV positive samples were collected from different prefectures of Yunnan province and their molecular epidemiological characters were determined. Phylogenetic analysis on the pre-S/S gene (865 bps) showed the prevalence of four HBV genotypes, including genotype B (24 cases, 33.3%), genotype C (45 cases, 62.5%), genotype I (two cases, 2.78%) and C/D recombinants (one case, 1.39%). The most prevalent genotypes B and C could be sub classified into subgenotype B2 and C1, C2, C5, and C7, respectively. Clusters of subgenotype B2 and C2 consisted of strains from China and other East Asian countries, while subgenotype C1, C5, and C7 and genotype I formed a cluster together with strains from Southeast Asia. Using Bayesian inference from phylogenetic, HBV genotypes B and C were estimated to have originated in 1860s and 1910s with an evolutionary rate of 3.26 and 8.01 × 10−4 substitutions/site/year, respectively. These findings indicate that the distribution of HBV genotypes in Yunnan was influenced by strains from the rest of China and the neighboring countries. J. Med. Virol. 86: 1675-1682, 2014. © 2014 The Authors. Journal of Medical Virology Published by Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Fluids with thermally conductive nanoparticles can provide improved heat transfer. Practical nanofluids will be likely based on lubricating oils for the continuous phase and systems that have extended service temperature ranges. A model system based on poly(α-olefin) synthetic base oil modified with poly(dimethylsiloxane) to lower the mixture's pour point with graphite as a conductive additive was studied. Phase separation of the oligomer mixture occurred at temperatures less than -15°C. Graphite particles were etched using citric acid pretreatment to create hydroxyl and carboxyl groups on their surfaces. A coupling reaction between the hydroxyl groups on graphite and chloro groups on silanes gave rise to poly(α-olefin)-philic graphite particles. Similarly, a coupling reaction between the carboxyl groups on graphite surface and amine groups on silanes gave rise to poly(dimethylsiloxane)-philic graphite particles. SEM, FT-IR, and TG-MS measurements were used to verify the presence of coupling agents on the surface and to estimate the thickness of the coatings. Upon separation of the mixture, each functionalized graphite type migrated exclusively to its preferred phase. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012 [ABSTRACT FROM AUTHOR]

Phase change materials (PCMs) have attracted increasing attention due to their efficient heat storage capability and small temperature fluctuation. And encapsulation has been recognized as an effective method to solve issues such as corrosion and leakage. For a long time, restricted by thermal expansion, encapsulation of PCMs has remained in the low‐temperature field and liquid‐state coating. In recent years, with the expansion of PCMs encapsulation into the medium and high temperature field and the development of solid‐state coating technology, encapsulation methods that consider thermal expansion have greatly improved the cycle life of encapsulated PCMs and make solid‐state coating of medium and high temperature PCMs possible. Herein, first, this paper summarizes the thermal expansion rates of common core and shell materials, as well as the thermal expansion behavior and stress analysis within confined spaces, proposing the necessity to solve thermal expansion issues. Subsequently, the solution strategies for solving thermal expansion issues in both macrocapsules and microcapsules are introduced. On this basis, the advantages and disadvantages of each strategy have been compared, and the applications of encapsulated PCMs after resolving thermal expansion issues have been introduced. Finally, the current issues, corresponding solutions, and future research directions have been put forward. [ABSTRACT FROM AUTHOR]