Yu Zhang

Recent reports from 2023 and 2024 have brought to light alarming instances of healthcare professionals in China being involved in commercial surrogacy arrangements. These cases reveal the dual roles these professionals play: active facilitation, which includes actions such as selling fraudulent birth certificates that contribute to baby trafficking, and passive involvement, where routine medical care is provided to surrogate mothers without full awareness of the surrogacy context. Current regulations in China broadly prohibit surrogacy-related medical activities but fail to differentiate between healthcare professionals who actively facilitate surrogacy arrangements and those who fulfil their professional obligations to patients. Drawing on professional ethics outlined in the revised 2021 Medical Practitioners Law of the People’s Republic of China and recent developments in modern slavery scholarship that emphasize the critical role of healthcare professionals in identifying and preventing exploitation, this paper argues that China has an opportunity to clarify and broaden the role of healthcare professionals in the context of surrogacy. Healthcare professionals should not be prohibited from providing medical care to surrogate mothers, provided they are not actively facilitating surrogacy arrangements. Simultaneously, they should be empowered to act as gatekeepers against exploitation. This would be an important step toward enhancing the current regulatory framework, ensuring better protections for children and women involved in surrogacy.

Although activated spinal cord glia contribute importantly to neuropathic pain, how nerve injury activates glia remains controversial. It has recently been proposed, on the basis of genetic approaches, that toll-like receptor 4 may be a key receptor for initiating microglial activation following L5 spinal nerve injury. The present studies extend this idea pharmacologically by showing that TLR4 is key for maintaining neuropathic pain following sciatic nerve chronic constriction injury. Established neuropathic pain was reversed by intrathecally delivered TLR4 receptor antagonists derived from lipopolysaccharide. Additionally, -naltrexone, -naloxone, and -naloxone, which we show here to be TLR4 antagonists in vitro on both stably transfected HEK293-TLR4 and microglial cell lines, suppressed neuropathic pain with complete reversal upon chronic infusion. Immunohistochemical analyses of spinal cords following chronic infusion revealed suppression of CCI-induced microglial activation by -naloxone and -naloxone, paralleling reversal of neuropathic pain. Together, these CCI data support the conclusion that neuron-to-glia signaling through TLR4 is important not only for initiating neuropathic pain, as suggested previously, but also for maintaining established neuropathic pain. Furthermore, these studies suggest that the novel TLR4 antagonists -naloxone and -naloxone can each fully reverse established neuropathic pain upon multi-day administration. This finding with -naloxone is of potential clinical relevance. This is because -naloxone is an antagonist that is inactive at the -opioid selective receptors on neurons that produce analgesia. Thus, these data suggest that -opioid antagonists such as -naloxone may be useful clinically to suppress glial activation, yet -opioid agonists suppress pain.

The BP neural network model is a hot issue in recent academic research, and it has been successfully applied to many other fields, but few researchers apply the BP neural network model to the field of automobile insurance. The main method that has been used in the prediction of the total claim amount in automobile insurance is the generalized linear model, where the BP neural network model could provide a different approach to estimate the total claim loss. This paper uses a genetic algorithm to optimize the structure of the BP neural network at first, and the calculation speed is significantly improved. At the same time, by considering the overfitting problem, an early stop method is introduced to avoid the overfitting problem. In the model, a three-layer BP neural network model, which includes the input layer, hidden layer, and output layer, is trained. With consideration of various factors, a total claim amount prediction model is established, and the trained BP neural network model is used to predict the total claim amount of automobile insurance based on the data of the training set. The results show that the accuracy of the prediction by using the BP neural network model to both the data of Shandong Province and to the data of six cities is over 95%. Then, the predicted total claim amount is used to calculate premiums for five cities in Shandong Province according to credibility theory. The results show that the average premium of the five cities is slightly higher than the actual claim amount of the city. The combination of BP neural network and credibility theory can perform accurate claim amount estimation and pricing for automobile insurance, which can effectively improve the current situation of the automobile insurance business and promote the development of insurance industry.

Adenosine‐to‐inosine (A‐to‐I) RNA editing, capable of protein recoding, has evolved independently in animals and fungi. This study proposes adaptive hypotheses regarding its origins and phenotypic significance, suggesting that A‐to‐I editing enhances adaptability by alleviating genetic trade‐offs. In metazoans, its emergence may have been driven by a development‐defense trade‐off associated with transposable element activation during the evolution of multicellularity. Late Devonian cooling and End‐Permian warming are hypothesized to have driven the emergence of extensive A‐to‐I recoding in coleoid nervous systems and Sordariomycete sexual fruiting bodies, respectively. These adaptations may have influenced key evolutionary innovations, including the evolution of metazoan nervous systems, coleoid intelligence, and shell loss, and fungal sexual reproductive structures. Additionally, extensive A‐to‐I recoding is proposed to facilitate accelerated development and specific life‐history strategies in both animals and fungi. This paper provides new perspectives on the evolutionary forces shaping A‐to‐I RNA editing and its role in phenotypic diversity across taxa.

This paper addresses the sliding mode control problem for a class of networked control systems with long time delay and consecutive packet dropout. A new modeling method is proposed, through which time delay and packet dropout are modeled in a unified model described by one Markov chain. To avoid the chattering problem of classic reaching law, a new chattering-free reaching law is proposed. Then with a focus on the problem that controller-actuator channel network condition cannot be foreseen by the controller, a new compensation strategy is proposed, which can effectively compensate for the effect of time delay and packet dropout in controller-actuator channel. Finally, a simulation example is presented to demonstrate the effectiveness of the proposed approach.

Specific to the NCSs where sensor signals can be processed centrally, a collaborative design scheme of dynamic game scheduling and advanced control theory was proposed in the present study. Firstly, by using the Jordan standard state space equation of the research object, the three elements of state noncooperative game were built, and the existence and uniqueness of Nash equilibrium solution were verified. In addition, the iterative equation of the scheduling matrix was derived by complying with the designed utility function. Secondly, refer to the number of restricted states the order of sliding mode was determined. And based on it, the corresponding sliding surface was designed. Subsequently, the quadratic optimization theory was adopted to regulate the control value following the implementation of the scheduling strategy to ensure that the control quality was further enhanced in the limited network service. Lastly, a TrueTime simulation example is established to verify the effectiveness of the proposed scheme.

In a commercialised and globalised China, museum institutions are pivotal elements in public strategies to present and create national self‐consciousness, insofar as their vast collections provide symbols of cultural identification on a national as well as an international level. This article will explore Chinese public museum policy and impact, firstly by describing the current status of the system as background information; secondly, by presenting the most recent trends in museum strategies and finally, by replacing the challenges and complexities of the museum system in a broader context. The analysis will draw from first hand material from interviews and informal conversations with museum professionals, small‐scale visitor surveys as well as the most recent facts and figures, and it will be illustrated by examples and supported by secondary sources.

© 2015 Macmillan Publishers Limited. All rights reserved.A single molecular layer of titanium diselenide is a promising material for advanced electronics beyond graphene - a strong focus of current research. Such molecular layers are at the quantum limit of device miniaturization and can show enhanced electronic effects not realizable in thick films. We show that single-layer TiSe2 exhibits a charge density wave transition at critical temperature TC =232±5 K, which is higher than the bulk TC =200±5 K. Angle-resolved photoemission spectroscopy measurements reveal a small absolute bandgap at room temperature, which grows wider with decreasing temperature T below TC in conjunction with the emergence of ordering. The results are rationalized in terms of first-principles calculations, symmetry breaking and phonon entropy effects. The observed Bardeen-Cooper-Schrieffer behaviour of the gap implies a mean-field CDW order in the single layer and an anisotropic CDW order in the bulk.

© The Author 2016.Topological quantum materials represent a new class of matter with both exotic physical phenomena and novel application potentials. Many Heusler compounds, which exhibit rich emergent properties such as unusual magnetism, superconductivity and heavy fermion behaviour, have been predicted to host non-trivial topological electronic structures. The coexistence of topological order and other unusual properties makes Heusler materials ideal platform to search for new topological quantum phases. By carrying out angle-resolved photoemission spectroscopy and ab initio calculations on rare-earth half-Heusler compounds LnPtBi, we directly observe the unusual topological surface states on these materials, establishing them as first members with non-trivial topological electronic structure in this class of materials. Moreover, as LnPtBi compounds are non-centrosymmetric superconductors, our discovery further highlights them as promising candidates of topological superconductors.

To better determine the history of modern birds, we performed a genome-scale phylogenetic analysis of 48 species representing all orders of Neoaves using phylogenomic methods created to handle genome-scale data.We recovered a highly resolved tree that confirms previously controversial sister or close relationships.We identified the first divergence in Neoaves, two groups we named Passerea and Columbea, representing independent lineages of diverse and convergently evolved land and water bird species. Among Passerea, we infer the common ancestor of core landbirds to have been an apex predator and confirm independent gains of vocal learning. Among Columbea, we identify pigeons and flamingoes as belonging to sister clades. Even with whole genomes, some of the earliest branches in Neoaves proved challenging to resolve, which was best explained by massive protein-coding sequence convergence and high levels of incomplete lineage sorting that occurred during a rapid radiation after the Cretaceous-Paleogene mass extinction event about 66 million years ago.

© 2013 Author. Nonlinear all-X-ray signals that involve large core-atom separation compared to the X-ray wavelengths may not be described by the dipole approximation since they contain additional phase factors. Expressions for the rotationally averaged 2D X-ray photon echo signals from randomly oriented systems that take this positiondependent phase into account for arbitrary ratio between the core separation and the resonant wavelength are presented. Application is made to the Se K-edge of a selenium dipeptide system.

Most MRI studies of Alzheimer's disease and frontotemporal dementia have assessed structural, perfusion and diffusion abnormalities separately while ignoring the relationships across imaging modalities. This paper aimed to assess brain gray and white matter abnormalities jointly to elucidate differences in abnormal MRI patterns between the diseases. Twenty AD, 20 FTD patients, and 21 healthy control subjects were imaged using a 4Tesla MRI. GM loss and GM hypoperfusion were measured using high-resolution T1 and arterial spin labeling MRI. WM degradation was measured with diffusion tensor imaging. Using a new analytical approach, the study found greater WM degenerations in FTD than AD at mild abnormality levels. Furthermore, the GM loss and WM degeneration exceeded the reduced perfusion in FTD whereas, in AD, structural and functional damages were similar. Joint assessments of multimodal MRI have potential value to provide new imaging markers for improved differential diagnoses between FTD and AD. Copyright © 2011 Yu Zhang et al.

© 2016 Elsevier B.V.The evaporative-cooling roof is a popular passive energy conservation technique. This article presents a novel approach for modelling and analysing the influence of evaporation on roof thermal performance. A multivariate nonlinear model was developed for the prediction of the evaporation rate from porous tile. A computer program was then developed based on the one-dimensional roof unsteady heat transfer theory. Finally, the computer program and hourly weather data of Guangzhou, China, were used to analyse the impacts of evaporation and slope orientation on roof thermal performance. Evaporation beginning at 11:00 can reduce the external surface temperatures of a horizontal roof and 30°-inclined east-sloping and west-sloping roofs by up to 11.3, 10.7, and 9.8 °C, respectively, from those of a non-evaporative roof. This, in turn, can reduce the peak-hour internal surface heat flux. Additionally, with the horizontal roof, the reduction in the peak-hour heat flux can be doubled if the evaporative layer is frequently replenished with water.

Topological insulators nanowires are an emerging class of structures, promising both novel quantum effects and potential applications in low-power electronics, thermoelectrics and spintronics. However, investigating the electronic states of TI NWs is complicated, due to their small lateral size, especially at room temperature. Here, we perform scanning probe based nanoscale imaging to resolve the local surface potential landscapes of Bi 2 Te 3 nanowires at 300 K. We found equipotential rings around the NWs perimeter that we attribute to azimuthal 1D modes. Along the NW axis, these modes are altered, forming potential ripples in the local density of states, due to intrinsic disturbances. Potential mapping of electrically biased NWs enabled us to accurately determine their conductivity which was found to increase with the decrease of NW diameter, consistent with surface dominated transport. Our results demonstrate that TI NWs can pave the way to both exotic quantum states and novel electronic devices.

© 2016 American Chemical Society.Layered transition metal chalcogenides with large spin orbit coupling have recently sparked much interest due to their potential applications for electronic, optoelectronic, spintronics, and valleytronics. However, most current understanding of the electronic structure near band valleys in momentum space is based on either theoretical investigations or optical measurements, leaving the detailed band structure elusive. For example, the exact position of the conduction band valley of bulk MoS2 remains controversial. Here, using angle-resolved photoemission spectroscopy with submicron spatial resolution, we systematically imaged the conduction/valence band structure evolution across representative chalcogenides MoS2, WS2, and WSe2, as well as the thickness dependent electronic structure from bulk to the monolayer limit. These results establish a solid basis to understand the underlying valley physics of these materials, and also provide a link between chalcogenide electronic band structure and their physical properties for potential valleytronics applications.

© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, WeinheimSuperconductivity in monolayer niobium diselenide on bilayer graphene is studied by electrical transport. Monolayer NbSe2 is grown on bilayer graphene by molecular beam epitaxy and capped with a selenium film to avoid degradation in air. The selenium capped samples have TC = 1.9 K. In situ measurements down to 4 K in ultrahigh vacuum show that the effect of the selenium layer on the transport is negligible. The superconducting transition and upper critical fields in air exposed and selenium capped samples are compared. Schematic of monolayer NbSe2/bilayer graphene with selenium capping layer and electrical contacts.

© 2016 American Physical Society.The nematic state, where a system is translationally invariant but breaks rotational symmetry, has drawn great attention recently due to the experimental observations of such a state in both cuprates and iron-based superconductors. The origin of nematicity and its possible tie to the pairing mechanism of high-Tc, however, still remain controversial. Here, we study the electronic structure of a multilayer FeSe film using angle-resolved photoemission spectroscopy. The band reconstruction in the nematic state is clearly delineated. We find that the energy splitting between dxz and dyz bands shows a nonmonotonic distribution in momentum space. From the Brillouin zone center to the Brillouin zone corner, the magnitude of splitting first decreases, then increases, and finally reaches the maximum value of ∼70 meV. Moreover, besides the dxz and dyz bands, band splitting was also observed on the dxy bands with a comparable energy scale around 45 meV. Our results suggest that the electronic anisotropy in the nematic state cannot be explained by a simple on-site ferro-orbital order. Instead, strong anisotropy exists in the hopping of all dxz,dyz, and dxy orbitals, the origin of which holds the key to a microscopic understanding of the nematicity in iron-based superconductors.

© 2016 American Chemical Society.High quality WSe2 films have been grown on bilayer graphene with layer-by-layer control of thickness using molecular beam epitaxy. The combination of angle-resolved photoemission, scanning tunneling microscopy/spectroscopy, and optical absorption measurements reveal the atomic and electronic structures evolution and optical response of WSe2/BLG. We observe that a bilayer of WSe2 is a direct bandgap semiconductor, when integrated in a BLG-based heterostructure, thus shifting the direct-indirect band gap crossover to trilayer WSe2. In the monolayer limit, WSe2 shows a spin-splitting of 475 meV in the valence band at the K point, the largest value observed among all the MX2 materials. The exciton binding energy of monolayer-WSe2/BLG is found to be 0.21 eV, a value that is orders of magnitude larger than that of conventional three-dimensional semiconductors, yet small as compared to other two-dimensional transition metal dichalcogennides semiconductors. Finally, our finding regarding the overall modification of the electronic structure by an alkali metal surface electron doping opens a route to further control the electronic properties of TMDCs.

© 2016 Macmillan Publishers Limited.Layered transition metal dichalcogenides are ideal systems for exploring the effects of dimensionality on correlated electronic phases such as charge density wave order and superconductivity. In bulk NbSe 2 a CDW sets in at T CDW = 33 K and superconductivity sets in at T c = 7.2 K. Below T c these electronic states coexist but their microscopic formation mechanisms remain controversial. Here we present an electronic characterization study of a single two-dimensional layer of NbSe 2 by means of low-temperature scanning tunnelling microscopy/spectroscopy, angle-resolved photoemission spectroscopy, and electrical transport measurements. We demonstrate that 3 × 3 CDW order in NbSe 2 remains intact in two dimensions. Superconductivity also still remains in the 2D limit, but its onset temperature is depressed to 1.9 K. Our STS measurements at 5 K reveal a CDW gap of= 4 meV at the Fermi energy, which is accessible by means of STS owing to the removal of bands crossing the Fermi level for a single layer. Our observations are consistent with the simplified electronic structure of single-layer NbSe 2, thus providing insight into CDW formation and superconductivity in this model strongly correlated system.

© 2015 American Physical Society.The level of electronic correlation has been one of the key questions in understanding the nature of superconductivity. Among the iron-based superconductors, the iron chalcogenide family exhibits the strongest electron correlations. To gauge the correlation strength, we performed a systematic angle-resolved photoemission spectroscopy study on the iron chalcogenide series Fe1+ySexTe1-x, a model system with the simplest structure. Our measurement reveals an incoherent-to-coherent crossover in the electronic structure as the selenium ratio increases and the system evolves from a weakly localized to a more itinerant state. Furthermore, we found that the effective mass of bands dominated by the dxy orbital character significantly decreases with increasing selenium ratio, as compared to the dxz/dyz orbital-dominated bands. The orbital-dependent change in the correlation level agrees with theoretical calculations on the band structure renormalization, and may help to understand the onset of superconductivity in Fe1+ySexTe1-x.

© 2015 American Institute of Chemical Engineers.Current lithium-ion batteries are predicted to be unable to provide the specific energy required to meet the ever-increasing demands of rapidly emerging technologies. Due to a high theoretical specific capacity of 1675 mAh/g, sulfur has gained much attention as a promising positive electrode material for high specific energy rechargeable batteries. Although the lithium/sulfur cell has been studied for many years and continues to receive much attention today as an alternative power source for zero-emission vehicles and advanced electronic devices, the realization of this novel cell's promise as a commercial product has yet to be successful. The major problems with sulfur electrodes involve: the dissolution of sulfur and the resulting diffusion of dissolved polysulfides and the deposition of insulating products on both the negative and the positive electrodes. These solid deposits can physically block the electrode reaction sites, thus passivating the electrode surfaces. Another important problem is the large volume change that occurs with the conversion of S to Li 2 S. It is important to understand that the performance of Li/S cells is hampered by linked chemical and mechanical degradations and both degradation mechanisms must be correctly alleviated in order to markedly improve current-technology Li/S cells. In this study, improved cycling performance via the reactive functional groups on graphene oxide to successfully immobilize sulfur and lithium polysulfides during operation has been demonstrated. The use of a new electrolyte and binder leads to improved cell performance in terms of high-rate capability and good reversibility, yielding at least 800 cycles have also been demonstrated.

Oxidative stress has been implicated in cardiac arrhythmia, although a causal relationship remains undefined. We have recently demonstrated a marked up-regulation of NADPH oxidase isoform 4 in patients with atrial fibrillation, which is accompanied by overproduction of reactive oxygen species. In this study, we investigated the impact on the cardiac phenotype of NOX4 overexpression in zebrafish. One-cell stage embryos were injected with NOX4 RNA prior to video recording of a GFP-labeled beating heart in real time at 24-31 h post-fertilization. Intriguingly, NOX4 embryos developed cardiac arrhythmia that is characterized by irregular heartbeats. When quantitatively analyzed by an established LQ-1 program, the NOX4 embryos displayed much more variable beat-to-beat intervals. Both the phenotype and the increased ROS in NOX4 embryos were attenuated by NOX4 morpholino co-injection, treatments of the embryos with polyethylene glycol-conjugated superoxide dismutase, or NOX4 inhibitors fulvene-5, 6-dimethylaminofulvene, and proton sponge blue. Injection of NOX4-P437H mutant RNA had no effect on the cardiac phenotype or ROS production. In addition, phosphorylation of calcium/cal-modulin-dependent protein kinase II was increased in NOX4 embryos but diminished by polyethylene glycol-conjugated superoxide dismutase, whereas its inhibitor KN93 or AIP abolished the arrhythmic phenotype. Taken together, our data for the first time uncover a novel pathway that underlies the development of cardiac arrhythmia, namely NOX4 activation, subsequent NOX4-specific NADPH-driven ROS production, and redox-sensitive CaMKII activation. These findings may ultimately lead to novel therapeutics targeting cardiac arrhythmia. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

Lithium/sulfur cells are receiving significant attention as an alternative power source for zero-emission vehicles and advanced electronic devices due to the very high theoretical specific capacity of the sulfur cathode. However, the poor cycle life and rate capability have remained a grand challenge, preventing the practical application of this attractive technology. Here, we report that a Li/S cell employing a cetyltrimethyl ammonium bromide -modified sulfur-graphene oxide nanocomposite cathode can be discharged at rates as high as 6C and charged at rates as high as 3C while still maintaining high specific capacity, with a long cycle life exceeding 1500 cycles and an extremely low decay rate, perhaps the best performance demonstrated so far for a Li/S cell. The initial estimated cell-level specific energy of our cell was ∼500 W·h/kg, which is much higher than that of current Li-ion cells. Even after 1500 cycles, we demonstrate a very high specific capacity, which corresponds to ∼414 mA·h/g of electrode: still higher than state-of-the-art Li-ion cells. Moreover, these Li/S cells with lithium metal electrodes can be cycled with an excellent Coulombic efficiency of 96.3% after 1500 cycles, which was enabled by our new formulation of the ionic liquid-based electrolyte. The performance we demonstrate herein suggests that Li/S cells may already be suitable for high-power applications such as power tools. Li/S cells may now provide a substantial opportunity for the development of zero-emission vehicles with a driving range similar to that of gasoline vehicles. © 2013 American Chemical Society.

Previous research has consistently demonstrated the importance of parents' expectations and adolescents' expectations on adolescents' academic achievement. Less is known, however, about the reciprocal relationships among these constructs. To address this issue, we analyzed two waves of data from the National Education Longitudinal Study of 1988 using longitudinal cross-lagged path models. The sample consisted of 14,376 students. Results indicated that there was a reciprocal relationship between parents' expectations and adolescents' expectations. Moreover, there was a reciprocal relationship between expectations and adolescents' academic achievement. Multiple-group analyses of gender and ethnicity revealed that the effects of parents' expectations on students' expectations were stronger among males than among females. With respect to ethnic differences, the effects of adolescents' expectations were weakest on parents' expectations among African Americans as compared to the other ethnic groups. Implications of these findings are discussed. © 2010 The Author.