China's green data center development:Policies and carbon reduction technology path.

Data center is a very important infrastructure to support the development of information technology, and its development and increment are very remarkable. However, with the rapid and large-scale development of data centers, the problem of energy consumption turns to be also very prominent. Under the background of global carbon peak and carbon neutrality, developing green and low-carbon data centers has become an inevitable trend. This paper reviews and analyzes the policies and their roles in promoting China's green development of data centers in the past 10 years, summarizes the current situation of the implementation of green data center projects in China and gives the changes of PUE limits of data centers under the policy constraints. Application of green technologies is an important measure for energy-saving and low-carbon development of data centers, so encouraging innovation and application of green technologies in data center is also a priority task in relevant policies. This paper points out the green and low-carbon technology system of data centers, further summarizes energy-saving and carbon-reducing technologies in IT equipment, cooling system, power supply and distribution system, lighting, intelligent operation and maintenance, and provides an outlook on the future green development of data centers.

Review of animal transmission experiments of respiratory viruses: Implications for transmission risk of SARS-COV-2 in humans via different routes.

Exploring transmission risk of different routes has major implications for epidemic control. However, disciplinary boundaries have impeded the dissemination of epidemic information, have caused public panic about "air transmission," "air-conditioning transmission," and "environment-to-human transmission," and have triggered "hygiene theater." Animal experiments provide experimental evidence for virus transmission, but more attention is paid to whether transmission is driven by droplets or aerosols and using the dichotomy to describe most transmission events. Here, according to characteristics of experiment setups, combined with patterns of human social interactions, we reviewed and grouped animal transmission experiments into four categories-close contact, short-range, fomite, and aerosol exposure experiments-and provided enlightenment, with experimental evidence, on the transmission risk of severe acute respiratory syndrome coronavirus (SARS-COV-2) in humans via different routes. When referring to "air transmission," context should be showed in elaboration results, rather than whether close contact, short or long range is uniformly described as "air transmission." Close contact and short range are the major routes. When face-to-face, unprotected, horizontally directional airflow does promote transmission, due to virus decay and dilution in air, the probability of "air conditioning transmission" is low; the risk of "environment-to-human transmission" highly relies on surface contamination and human behavior based on indirect path of "fomite-hand-mucosa or conjunctiva" and virus decay on surfaces. Thus, when discussing the transmission risk of SARS-CoV-2, we should comprehensively consider the biological basis of virus transmission, environmental conditions, and virus decay. Otherwise, risk of certain transmission routes, such as long-range and fomite transmission, will be overrated, causing public excessive panic, triggering ineffective actions, and wasting epidemic prevention resources.

Reducing Indoor Levels of "Outdoor PM2.5" in Urban China: Impact on Mortalities.

This study estimates adult mortalities attributed to PM2.5 across urban China in 2015 and the corresponding mortalities that might be avoided by meeting the yearly averaged indoor PM2.5 threshold in the newly established Assessment Standard for Healthy Building (ASHB) and seven other potential thresholds. We use outdoor PM2.5 concentrations from ∼1500 monitoring sites in 339 Chinese cities, coupled with a detailed exposure model, to estimate outdoor and indoor exposures to PM2.5 originating outdoors. We proceed to calculate premature mortality attributable to PM2.5 exposure using an integrated exposure-response model. Results indicate that indoor exposures accounted for 66%-87% of total exposure to PM2.5 of outdoor origin and 81% (95% confidence interval (CI), 71%-87%), i.e., 316 000 (95% CI, 176 000-435 000), of the 389 000 (95% CI, 245 000-501 000) mortalities attributable to "outdoor PM2.5" for the urban population ≥25 years of age in China in 2015. Potentially 14 000 (95% CI, 8000-20 000) deaths might be avoided if indoor PM2.5 of outdoor origin met the ASHB guideline of 35 µg/m3 for annual mean indoor PM2.5, and 162 000 (95% CI, 79 000-237 000) deaths might be avoided by meeting a 10 µg/m3 threshold. The analysis in this work should be helpful in formulating indoor air quality policies.

[Central cholinergic system innervates song control system of songbirds and regulates song behavior].

Songbird has become an ideal model for studying motor learning due to its unique learned song behavior. It has been proved that song behavior is directly regulated by song control system in the forebrain of songbirds. There are lines of evidence to show that cholinergic transmitters and their receptors are distributed in song control system, and vocal control nuclei in song control system are innervated by cholinergic nerves from the central cholinergic system in basal forebrain, which can affect activities of vocal control nuclei through cholinergic transmitters, and then affect song behavior. Studies in mammals have confirmed that the central cholinergic system is involved in the regulation of motor behavior and neural process of motor learning. Elucidation of regulation of songbirds' song behavior by central cholinergic system would shed light on the neural mechanism of song motor control and song learning and memory in songbirds, and provide theoretical insights for researches on other animals' sensorimotor processes and human language learning. This review summarized recent progresses, including the research work of our laboratory, in the studies on the selectivity of cholinergic transmitters to their receptors and their effects on neuronal activities in vocal control nuclei of songbirds and provided valuable clues for revealing the regulation mechanism of central cholinergic system on songbirds' song behavior.

BDNF enhances electrophysiological activity and excitatory synaptic transmission of RA projection neurons in adult male zebra finches.

The singing of songbirds is a complex vocal behavior. It was reported that brain-derived neurotrophic factor (BDNF), a key neurotrophic factor involved in neuronal survival and activity, plays an important role in regulation of songbirds' song behavior. In all song-related nuclei, the electrophysiological activity of robust nucleus of the arcopallium (RA) in the forebrain of songbirds is directly related to birdsong output. Whether BDNF regulates the electrophysiological activity and synaptic transmission of RA causing the change of song behavior need be further explored. In this study, the effects of BDNF on the electrophysiological activity and excitatory synaptic transmission of RA projection neurons (PNs) in adult male zebra finches were investigated using whole-cell patch clamp recordings in vitro. Our results showed that BDNF increased the firing of evoked action potentials in RA PNs and decreased the membrane input resistance and membrane time constant of RA PNs, indicating that BDNF can promote RA PNs excitability by reducing membrane input resistance and membrane time constant. Meanwhile, BDNF increased the frequency rather than amplitude of miniature excitatory postsynaptic currents (mEPSCs) in RA PNs. Moreover, the effects of BDNF on the excitability, intrinsic membrane properties and mEPSCs of RA PNs were blocked by its receptor TrkB antagonist K252a. These results indicate that BDNF via TrkB enhances the excitability and excitatory synaptic transmission of RA PNs in adult male songbirds through presynaptic mechanisms, suggesting a possible cellular mechanism by which BDNF regulates song behavior.

How do temperature, humidity, and air saturation state affect the COVID-19 transmission risk?

Environmental parameters have a significant impact on the spread of respiratory viral diseases (temperature (T), relative humidity (RH), and air saturation state). T and RH are strongly correlated with viral inactivation in the air, whereas supersaturated air can promote droplet deposition in the respiratory tract. This study introduces a new concept, the dynamic virus deposition ratio (α), that reflects the dynamic changes in viral inactivation and droplet deposition under varying ambient environments. A non-steady-state-modified Wells-Riley model is established to predict the infection risk of shared air space and highlight the high-risk environmental conditions. Findings reveal that a rise in T would significantly reduce the transmission of COVID-19 in the cold season, while the effect is not significant in the hot season. The infection risk under low-T and high-RH conditions, such as the frozen seafood market, is substantially underestimated, which should be taken seriously. The study encourages selected containment measures against high-risk environmental conditions and cross-discipline management in the public health crisis based on meteorology, government, and medical research.

User demands analysis of Eco-city based on the Kano model-An application to China case study.

Eco-cities have witnessed rapid growth in these years worldwide. As the Eco-cities entering operation stage gradually, more and more researchers have found that users (who are living or working in the Eco-cities) satisfaction is one of the most important factors to determine the success or failure of Eco-cities. Therefore, it is very important to investigate the user demands to attract more citizens willing to live or work in the Eco-cities, which will make the development of Eco-cities more sustainable and solid. The recent researches on user demands investigation and analysis in the Eco-cities mainly focused on understanding the user need itself, yet lack of research on the relationship between the user demand and user satisfaction. This paper initially introduced the Kano model analysis method to the research field of user demands in Eco-city, to explore the relationship between the user demand and user satisfaction. After proposing user demands library in Eco-city (including Land use, Ecological environment, Green building, Energy utilization, etc.), the user demands classification and importance analysis methods of Eco-city were proposed based on Kano model. The questionnaire survey for users of two Eco-cities in China as case study was conducted, consisted of user demand items questionnaire based on the Kano model and a questionnaire on the importance of the user demand items. By utilizing the integration of quantitative analysis methods based on the Kano model and Analytic Hierarchy Process (AHP) method, the final ranking of user demands importance was obtained. Comparing with the existing literatures in terms of user demands research for Eco-city, the user demands analysis method based on Kano model of this paper, is able to reveal the influence degree of user satisfaction towards the facilities and services provided in the Eco-city. The user demands analysis method can be used for other researchers worldwide to investigate and quantitively analyze user demands according to their local development situation and preference of Eco-city. The user demands analysis results obtained through this method, can benefit different stages of Eco-city.

Dopamine Modulates Excitatory Synaptic Transmission by Activating Presynaptic D1-like Dopamine Receptors in the RA Projection Neurons of Zebra Finches.

Songbirds are useful vertebrate study models for vocal learning and memory. The robust nucleus of the arcopallium (RA) receives synaptic inputs from both the posterior and anterior pathways of the song control system in songbirds. Hence, RA plays an important role in the control of singing. RA receives dopaminergic (DArgic) inputs that increase the excitability of RA projection neurons (PNs). However, the effects of DA on excitatory synaptic transmission are yet to be deciphered. In this study, the effects of DA on the excitatory synaptic transmission of the PNs in the RA of adult male zebra finches were investigated using a whole-cell patch-clamp recording. We observed that DA decreased the frequency of spontaneous excitatory postsynaptic currents (sEPSCs) and miniature excitatory postsynaptic currents (mEPSCs). The effects of DA were mimicked by the D1-like DA receptor (D1R) agonist, SKF-38393, but not the D2-like DA receptor (D2R) agonist, Quinpirole. Also, the effects of DA were blocked by D1R antagonist, SCH-23390, but not the D2R antagonist, Sulpiride. These results demonstrate that DA modulates excitatory synaptic transmission by acting on D1R in the RA of adult male zebra finches.

Cloning and characterization of endolysin and holin from Streptomyces avermitilis bacteriophage phiSASD1 as potential novel antibiotic candidates.

Bacteriophages (phages), or bacterial viruses, have recently received increasing attention, especially considering pan-drug-resistant bacteria, and studies on lytic bacteriophage proteins would help develop antibiotic candidates to treat these bacterial infections. We previously isolated and sequenced a Streptomyces avermitilis bacteriophage, phiSASD1. This study aimed to clone and express ORF40 and ORF19, previously predicted as endolysin (termed LytSD) and holin (termed HolSD), two crucial phage proteins involved in host lysis. The yield of LytSD was 17.2 mg per liter of culture, and the optimal lysis conditions were investigated. When applied exogenously, LytSD lysed 7/18 of the tested bacterial strains, including S. avermitilis, Bacillus subtilis, Staphylococcus aureus, Sarcina lutea, and Enterococcus faecalis. As regards HolSD, it resulted in growth inhibition of several tested strains and abrupt lysis of E. coli BL21 (DE3) pLysS; furthermore, it complemented the defective λ S allele of non-suppressing E. coli strains to produce phage plaques. Together, these results indicate the function of ORF40 and ORF19 of phage phiSASD1 and their potentials as novel antibiotics to inhibit or lyse pathogens.

Photoactivated oxidase mimetics derived from dicyandiamide and barbituric acid for colorimetric detection of glutathione.

In this work, photoactivated oxidase mimetics was prepared by copolymerizing dicyandiamide with barbituric acid (BA) and characterized by X-ray diffraction pattern, Fourier transformed infrared spectrum, X-ray photoelectron spectroscopy, transmission electron microscopy, photoluminescence spectrum, diffuse reflectance spectrum. Experimental results and density functional theory calculation indicated that the substitution of nitrogen atoms by carbon atoms in tri-s-triazine structure due to the copolymerization of BA enhanced visible light absorption and weakened the barrier of photocarrier transfer. In the presence of visible light and oxygen, 3, 3', 5, 5'-tetramethylbenzidine was oxidized under the catalysis of photoactivated oxidase mimetics to produce a green colored product, which could be reduced by glutathione (GSH). Therefore, a facile method based on the photoactivated oxidase mimetic has been developed for colorimetric detection of GSH. The linear range for GSH was ranged from 2.0 to 50.0 µmol L-1 (R2 = 0.998) with the detection limit of 1.4 µmol L-1. The proposed method was applied to detect the cellular GSH with satisfactory results.

A Study on the Design Method of Indoor Fine Particulate Matter (PM2.5) Pollution Control in China.

Airborne fine particulate matter (PM2.5) is an important factor affecting indoor air quality and is significantly related to human health. A lot of research has been done on PM2.5 pollution control in buildings, but there is lack of systematic indoor PM2.5 pollution control for engineering applications. In this study, first, we propose an outdoor calculated concentration of PM2.5 in 74 cities, in China, using the "not guaranteed for five days" method, which is based on outdoor PM2.5 concentration monitoring data from 2016 to 2018. Then, different levels of indoor calculated concentrations of PM2.5 (25 µg/m3, 35 µg/m3, and 75 µg/m3) are put forward. Secondly, methods for selecting air purification equipment in centralized, semi-centralized, and decentralized air conditioning systems are proposed. Finally, PM2.5 pollution control measures and system energy-saving operation strategies in buildings are put forward. This study stipulates the calculation of PM2.5 concentration, unifies design methods, proposes control measures, and standardizes operations management. The aim of this study is to provide technical guidance for engineering design, construction and operation, and therefore to reduce the risk of indoor diseases caused by exposure to PM2.5.

Sexual dimorphism of inhibitory synaptic transmission in RA projection neurons of songbirds.

The song control system in the brain of songbirds is important for the production and acquisition of song and exhibits some of the largest neural sex differences observed in vertebrates. The robust nucleus of the arcopallium (RA) is a premotor nucleus, playing a key role in controlling singing. RA projection neurons (PNs) receives denser synapse inputs including excitatory in males than in females. However, the inhibitory synaptic transmission in the RA has not been reported. In the present study, using whole-cell voltage-clamp recording, spontaneous inhibitory postsynaptic currents (sIPSCs) and miniature inhibitory postsynaptic currents (mIPSCs) of the males and females were recorded. The average frequency and amplitude of sIPSCs/mIPSCs in males were higher than females. These results demonstrate the sexually dimorphic of the inhibitory synaptic transmission in the RA PNs and the RA PNs in males receive more inhibitory synaptic transmission. These findings contribute to further illuminate the neural mechanisms under the sexually dimorphism song production of adult zebra finches.

Association of interleukin-10 gene promoter polymorphisms with recurrent miscarriage: a meta-analysis.

PROBLEM: The association between IL-10 gene promoter polymorphisms and the risk of recurrent miscarriages (RM) remains controversial. The present meta-analysis was performed to derive a precise estimate of the relationship. METHOD OF STUDY: We searched the PubMed and EMBASE for studies related to the association between the IL-10 gene polymorphism and the risk of RM. Summary odds ratio (OR) with 95% confidence interval (CI) was estimated to assess the associations. RESULTS: Thirteen studies, including 2047 RM cases and 2055 control samples, were identified. The results showed a significant association between rs1800896, rs1800871 and RM risk (for rs1800896: GA+GG vs AA: OR=1.20, 95% CI=1.04-1.39, P=.02; for rs1800871: CT+TT vs CC: OR=1.64, 95% CI=1.13-2.36, P=.009). No evidence of association was noted between rs1800872 haplotype and RM risk. CONCLUSION: IL-10 gene promoter polymorphisms, rs1800896 and rs1800871, play a potential role in increasing the risk of RM.