Entropic and Near-Field Improvements of Thermoradiative Cells

A p-n junction maintained at above ambient temperature can work as a heat engine, converting some of the supplied heat into electricity and rejecting entropy by interband emission. Such thermoradiative cells have potential to harvest low-grade heat into electricity. By analyzing the entropy content of different spectral components of thermal radiation, we identify an approach to increase the efficiency of thermoradiative cells via spectrally selecting long-wavelength photons for radiative exchange. Furthermore, we predict that the near-field photon extraction by coupling photons generated from interband electronic transition to phonon polariton modes on the surface of a heat sink can increase the conversion efficiency as well as the power generation density, providing more opportunities to efficiently utilize terrestrial emission for clean energy. An ideal InSb thermoradiative cell can achieve a maximum efficiency and power density up to 20.4 % and 327 Wm-2, respectively, between a hot source at 500K and a cold sink at 300K. However, sub-bandgap and non-radiative losses will significantly degrade the cell performance

Heat meets light on the nanoscale

We discuss the state-of-the-art and remaining challenges in the fundamental understanding and technology development for controlling light-matter interactions in nanophotonic environments in and away from thermal equilibrium. The topics covered range from the basics of the thermodynamics of light emission and absorption, to applications in solar-thermal energy generation, thermophotovoltaics, optical refrigeration, personalized cooling technologies, development of coherent incandescent light sources, and spinoptics.Comment: 46 pages, 11 figures; to appear in the special issue of Nanophotonics on 'Smart nanophotonics for renewable energy and sustainability' 201

Linking young men who have sex with men (YMSM) to STI physicians: a nationwide cross-sectional survey in China.

BACKGROUND: Many young men who have sex with men (YMSM) are reluctant to seek health services and trust local physicians. Online information seeking may encourage YMSM to identify and see trustworthy physicians, obtain sexual health services, and obtain testing for sexually transmitted infections (STIs). This study examined online STI information seeking behaviors among Chinese YMSM and its association with offline physician visits. METHODS: We conducted a nationwide online survey among YMSM through WeChat, the largest social media platform in China. We collected information on individual demographics, sexual behaviors, online STI information seeking, offline STI testing, and STI physician visits. We examined the most commonly used platforms (search engines, governmental websites, counseling websites, generic social media, gay mobile apps, and mobile medical apps) and their trustworthiness. We assessed interest and willingness to use an MSM-friendly physician finder function embedded within a gay mobile app. Logistic regression models were used to examine the correlation between online STI information searching and offline physician visits. RESULTS: A total of 503 men completed the survey. Most men (425/503, 84.5%) searched for STI information online. The most commonly used platform to obtain STI information were search engines (402/425, 94.5%), followed by gay mobile apps (201/425, 47.3%). Men reported high trustworthiness of information received from gay mobile apps. Men also reported high interest (465/503, 92.4%) and willingness (463/503, 92.0%) to use a MSM-friendly physician finder function within such apps. Both using general social media (aOR =1.14, 95%CI: 1.04-1.26) and mobile medical apps (aOR =1.16, 95%CI: 1.01-1.34) for online information seeking were associated with visiting a physician. CONCLUSION: Online STI information seeking is common and correlated with visiting a physician among YMSM. Cultivating partnerships with the emerging mobile medical apps may be useful for disseminating STI information and providing better physician services to YMSM

Modeling the System Parameters of 2M1533+3759: A New Longer-Period Low-Mass Eclipsing sdB+dM Binary

We present new photometric and spectroscopic observations for 2M 1533+3759 (= NSVS 07826147). It has an orbital period of 0.16177042 day, significantly longer than the 2.3--3.0 hour periods of the other known eclipsing sdB+dM systems. Spectroscopic analysis of the hot primary yields Teff = 29230 +/- 125 K, log g = 5.58 +/- 0.03 and log N(He)/N(H) = -2.37 +/- 0.05. The sdB velocity amplitude is K1 = 71.1 +/- 1.0 km/s. The only detectable light contribution from the secondary is due to the surprisingly strong reflection effect. Light curve modeling produced several solutions corresponding to different values of the system mass ratio, q(M2/M1), but only one is consistent with a core helium burning star, q=0.301. The orbital inclination is 86.6 degree. The sdB primary mass is M1 = 0.376 +/- 0.055 Msun and its radius is R1 = 0.166 +/- 0.007 Rsun. 2M1533+3759 joins PG0911+456 (and possibly also HS2333+3927) in having an unusually low mass for an sdB star. SdB stars with masses significantly lower than the canonical value of 0.48 Msun, down to as low as 0.30 Msun, were theoretically predicted by Han et al. (2002, 2003), but observational evidence has only recently begun to confirm the existence of such stars. The existence of core helium burning stars with masses lower than 0.40--0.43 Msun implies that at least some sdB progenitors have initial main sequence masses of 1.8--2.0 Msun or more, i.e. they are at least main sequence A stars. The secondary is a main sequence M5 star.Comment: 47 pages, 7 figure

Linking young men who have sex with men (YMSM) to STI physicians: a nationwide cross-sectional survey in China

Abstract Background Many young men who have sex with men (YMSM) are reluctant to seek health services and trust local physicians. Online information seeking may encourage YMSM to identify and see trustworthy physicians, obtain sexual health services, and obtain testing for sexually transmitted infections (STIs). This study examined online STI information seeking behaviors among Chinese YMSM and its association with offline physician visits. Methods We conducted a nationwide online survey among YMSM through WeChat, the largest social media platform in China. We collected information on individual demographics, sexual behaviors, online STI information seeking, offline STI testing, and STI physician visits. We examined the most commonly used platforms (search engines, governmental websites, counseling websites, generic social media, gay mobile apps, and mobile medical apps) and their trustworthiness. We assessed interest and willingness to use an MSM-friendly physician finder function embedded within a gay mobile app. Logistic regression models were used to examine the correlation between online STI information searching and offline physician visits. Results A total of 503 men completed the survey. Most men (425/503, 84.5%) searched for STI information online. The most commonly used platform to obtain STI information were search engines (402/425, 94.5%), followed by gay mobile apps (201/425, 47.3%). Men reported high trustworthiness of information received from gay mobile apps. Men also reported high interest (465/503, 92.4%) and willingness (463/503, 92.0%) to use a MSM-friendly physician finder function within such apps. Both using general social media (aOR =1.14, 95%CI: 1.04–1.26) and mobile medical apps (aOR =1.16, 95%CI: 1.01–1.34) for online information seeking were associated with visiting a physician. Conclusion Online STI information seeking is common and correlated with visiting a physician among YMSM. Cultivating partnerships with the emerging mobile medical apps may be useful for disseminating STI information and providing better physician services to YMSM

Effects of acidification on nitrification and associated nitrous oxide emission in estuarine and coastal waters

In the context of an increasing atmospheric carbon dioxide (CO2) level, acidification of estuarine and coastal waters is greatly exacerbated by land-derived nutrient inputs, coastal upwelling, and complex biogeochemical processes. A deeper understanding of how nitrifiers respond to intensifying acidification is thus crucial to predict the response of estuarine and coastal ecosystems and their contribution to global climate change. Here, we show that acidification can significantly decrease nitrification rate but stimulate generation of byproduct nitrous oxide (N2O) in estuarine and coastal waters. By varying CO2 concentration and pH independently, an expected beneficial effect of elevated CO2 on activity of nitrifiers (“CO2-fertilization” effect) is excluded under acidification. Metatranscriptome data further demonstrate that nitrifiers could significantly up-regulate gene expressions associated with intracellular pH homeostasis to cope with acidification stress. This study highlights the molecular underpinnings of acidification effects on nitrification and associated greenhouse gas N2O emission, and helps predict the response and evolution of estuarine and coastal ecosystems under climate change and human activities.publishedVersio

Identifying MSM-competent physicians in China: a national online cross-sectional survey among physicians who see male HIV/STI patients

Abstract Background Men who have sex with men (MSM) are at high risk of human immunodeficiency virus (HIV) infection and sexually transmitted infection (STI) in China. Inadequate clinical services and poor clinical competency among physicians are major barriers to improving the sexual health of MSM. This study aims to understand physician clinical competency in providing MSM health services in China. Methods We conducted an online cross-sectional survey among Chinese physicians who have seen male patients for STI complaints in the past year. We obtained information on individual demographics, clinical practice, attitudes toward MSM, and interest in contributing to MSM clinical services. We defined an MSM-competent physician as one who asked male patients about sexual orientation, sexual practices, and recommended HIV/ STI testing during a clinic visit. We conducted multivariable logistic regression to identify factors associated with MSM competency. Results In total, 501 physicians completed the survey. The most common subspecialties were dermatovenereology (33.1%), urology (30.1%), and general medicine (14.4%). Roughly half (n = 267, 53.3%) reported seeing MSM in the past 12 months. Among physicians who saw MSM in the past 12 months, 60.3% (n = 161) met criteria as MSM-competent physicians, and most (n = 234, 87.6%) MSM-competent physicians reported positive or neutral attitudes towards MSM. Over 60% of all physicians were willing to participate in activities for improving MSM services, such as training and being on a list of physicians willing to serve MSM. MSM-competent physicians showed no sociodemographic differences compared with non MSM-competent physicians. MSM-competent physicians were more willing to have their medical institution named on a public clinic list capable of serving MSM (aOR: 1.70, 95%CI: 1.01–2.86) and being on a public physician list capable of serving MSM (aOR: 1.77, 95%CI: 1.03–3.03). Conclusions MSM-competent physicians included a broad range of individuals that practiced in diverse clinical settings. Most physicians were interested in improving and expanding MSM clinical services, despite having neutral attitudes toward same-sex behavior. Future interventions should focus on developing MSM clinical competency and expanding services that meet the needs of MSM

Identifying MSM-competent physicians in China: a national online cross-sectional survey among physicians who see male HIV/STI patients.

BACKGROUND: Men who have sex with men (MSM) are at high risk of human immunodeficiency virus (HIV) infection and sexually transmitted infection (STI) in China. Inadequate clinical services and poor clinical competency among physicians are major barriers to improving the sexual health of MSM. This study aims to understand physician clinical competency in providing MSM health services in China. METHODS: We conducted an online cross-sectional survey among Chinese physicians who have seen male patients for STI complaints in the past year. We obtained information on individual demographics, clinical practice, attitudes toward MSM, and interest in contributing to MSM clinical services. We defined an MSM-competent physician as one who asked male patients about sexual orientation, sexual practices, and recommended HIV/ STI testing during a clinic visit. We conducted multivariable logistic regression to identify factors associated with MSM competency. RESULTS: In total, 501 physicians completed the survey. The most common subspecialties were dermatovenereology (33.1%), urology (30.1%), and general medicine (14.4%). Roughly half (n = 267, 53.3%) reported seeing MSM in the past 12 months. Among physicians who saw MSM in the past 12 months, 60.3% (n = 161) met criteria as MSM-competent physicians, and most (n = 234, 87.6%) MSM-competent physicians reported positive or neutral attitudes towards MSM. Over 60% of all physicians were willing to participate in activities for improving MSM services, such as training and being on a list of physicians willing to serve MSM. MSM-competent physicians showed no sociodemographic differences compared with non MSM-competent physicians. MSM-competent physicians were more willing to have their medical institution named on a public clinic list capable of serving MSM (aOR: 1.70, 95%CI: 1.01-2.86) and being on a public physician list capable of serving MSM (aOR: 1.77, 95%CI: 1.03-3.03). CONCLUSIONS: MSM-competent physicians included a broad range of individuals that practiced in diverse clinical settings. Most physicians were interested in improving and expanding MSM clinical services, despite having neutral attitudes toward same-sex behavior. Future interventions should focus on developing MSM clinical competency and expanding services that meet the needs of MSM