Hidden hotspots of amphibian biodiversity in China.

Identifying and protecting hotspots of endemism and species richness is crucial for mitigating the global biodiversity crisis. However, our understanding of spatial diversity patterns is far from complete, which severely limits our ability to conserve biodiversity hotspots. Here, we report a comprehensive analysis of amphibian species diversity in China, one of the most species-rich countries on Earth. Our study combines 20 y of field surveys with new molecular analyses of 521 described species and also identifies 100 potential cryptic species. We identify 10 hotspots of amphibian diversity in China, each with exceptional species richness and endemism and with exceptional phylogenetic diversity and phylogenetic endemism (based on a new time-calibrated, species-level phylogeny for Chinese amphibians). These 10 hotspots encompass 59.6% of China's described amphibian species, 49.0% of cryptic species, and 55.6% of species endemic to China. Only four of these 10 hotspots correspond to previously recognized biodiversity hotspots. The six new hotspots include the Nanling Mountains and other mountain ranges in South China. Among the 186 species in the six new hotspots, only 9.7% are well covered by protected areas and most (88.2%) are exposed to high human impacts. Five of the six new hotspots are under very high human pressure and are in urgent need of protection. We also find that patterns of richness in cryptic species are significantly related to those in described species but are not identical.

Evolution Characteristics of Void in the Caving Zone Using Fiber Optic Sensing.

Addressing the issue of low filling efficiency in gangue slurry backfilling due to unclear evolution characteristics of voids in the overlying collapsed rock mass during mining, this study utilizes fiber optic sensing technology to monitor real-time strain changes within the rock mass. It proposes a void zoning method based on fiber optic sensing for mining the overlying rock and, in combination with physical model experiments, systematically investigates the dimensions, distribution, and deformation characteristics of rock mass voids. By analyzing fiber optic sensing data, the correlation between the rate of void expansion and the stress state of the rock mass is revealed. The research results demonstrate that as mining progresses, the internal voids of the rock mass gradually expand, exhibiting complex spatial distribution patterns. During the mining process, the expansion of voids within the overlying collapsed rock mass is closely related to the stress state of the rock mass. The rate of void expansion is influenced by changes in stress, making stress regulation a key factor in preventing void expansion and rock mass instability. The application of fiber optic sensing technology allows for more accurate monitoring of changes in rock mass voids, enabling precise zoning of voids in the overlying collapsed rock mass during mining. This zoning method has been validated against traditional theoretical calculations and experimental results. This research expands our understanding of the evolution characteristics of voids in overlying collapsed rock mass and provides valuable reference for backfilling engineering practices and backfilling parameter optimization.

Overview of Health-Monitoring Technology for Long-Distance Transportation Pipeline and Progress in DAS Technology Application.

There are various health issues associated with the different stages of long-distance pipeline transportation. These issues pose potential risks to environmental pollution, resource waste, and the safety of human life and property. It is essential to have real-time knowledge of the overall health status of pipelines throughout their entire lifecycle. This article investigates various health-monitoring technologies for long-distance pipelines, providing references for addressing potential safety issues that may arise during long-term transportation. This review summarizes the factors and characteristics that affect pipeline health from the perspective of pipeline structure health. It introduces the principles of major pipeline health-monitoring technologies and their respective advantages and disadvantages. The review also focuses on the application of Distributed Acoustic Sensing (DAS) technology, specifically time and space continuous monitoring technology, in the field of pipeline structure health monitoring. This paper discusses the process of commercialization development of DAS technology, the main research progress in the experimental field, and the open research issues. DAS technology has broad application prospects in the field of long-distance transportation pipeline health monitoring.

Atomically Strained Metal Sites for Highly Efficient and Selective Photooxidation.

Strain engineering is an attractive strategy for improving the intrinsic catalytic performance of heterogeneous catalysts. Manipulating strain on the short-range atomic scale to the local structure of the catalytic sites is still challenging. Herein, we successfully achieved atomic strain modulation on ultrathin layered vanadium oxide nanoribbons by an ingenious intercalation chemistry method. When trace sodium cations were introduced between the V2O5 layers (Na+-V2O5), the V-O bonds were stretched by the atomically strained vanadium sites, redistributing the local charges. The Na+-V2O5 demonstrated excellent photooxidation performance, which was approximately 12 and 14 times higher than that of pristine V2O5 and VO2, respectively. Complementary spectroscopy analysis and theoretical calculations confirmed that the atomically strained Na+-V2O5 had a high surficial charge density, improving the activation of oxygen molecules and contributing to the excellent photocatalytic property. This work provides a new approach for the rational design of strain-equipped catalysts for selective photooxidation reactions.

Synthesis of a DNA-Encoded Macrocyclic Library Utilizing Intramolecular Benzimidazole Formation.

Macrocycles occupy chemical space "beyond the rule of five". They bridge traditional bioactive small molecule drugs and macromolecules and have the potential to modulate challenging targets such as PPI or proteases. Here we report an on-DNA macrocyclization reaction utilizing intramolecular benzimidazole formation. A 129-million-member macrocyclic library composed of a privileged benzimidazole core, a dipeptide sequence (natural or non-natural), and linkers of varying length and flexibility was designed and synthesized.

Long-period D-fiber grating based robust and efficient bidirectional coupler for whispering gallery mode excitation.

A robust and efficient bidirectional coupler for whispering gallery mode (WGM) excitation based on a long-period grating (LPG) inscribed in D-fiber is theoretically and experimentally demonstrated. The LPG coupling the fundamental core mode to the forward propagating cladding modes according to the phase-matching condition not only enhances the evanescent field of the fiber but also selectively excites the WGM in a wavelength band of interest. Experimental results show that a maximum resonance contrast as high as 10.5 dB and a quality factor (Q-factor) on the order of 104 can be achieved in an LPG coupled spherical silica WGM resonator with a diameter of 242 µm, where the LPG with a pitch of 680 µm is fabricated by arc-discharging in a side-polished D-fiber with a maximum polishing depth of 56 µm. In addition to high robustness and efficiency, such an LPG-based WGM coupler also demonstrates bidirectionality, i.e., it is independent of the injection direction of the input light, which provides a reliable and flexible fiber coupler for the WGM resonator based practical applications.

Narrow linewidth semiconductor multi-wavelength DFB laser array simultaneously self-injection locked to a single microring resonator.

We experimentally demonstrate a narrow linewidth semiconductor multi-wavelength distributed feedback (DFB) laser array by simultaneously injection locking each laser to the corresponding resonance of a single on-chip microring resonator. The white frequency noises of all the DFB lasers is reduced by more than 40 dB once they are simultaneously injection locked to a single microring resonator with a quality factor (Q-factor) of 2.38 million. Correspondingly, the instantaneous linewidths of all the DFB lasers are narrowed by a factor of 104. In addition, frequency combs originating from non-degenerate four-wave mixing (FWM) between the locked DFB lasers are also observed. Simultaneously injection locking multi-wavelength lasers to a single on-chip resonator may enable the possibilities of integrating a narrow-linewidth semiconductor laser array on a single chip and having multiple microcombs in a single resonator, which are in high demand in wavelength division multiplexing coherent optical communication systems and metrological applications.

Prelimbic cortex dynorphin/κ opioid receptor system modulates methamphetamine-induced cognitive impairment.

Chronic exposure to methamphetamine (METH) causes severe and persistent cognitive impairment. The present study aimed to investigate the role of dynorphin/κ opioid receptor (KOR) system in the development of METH-induced cognitive impairment. We found that mice showed significant cognitive impairment in the novel object recognition test (NOR) following daily injections of METH (10 mg/kg) for seven consecutive days. Systemic blockade of KOR prevented METH-induced cognitive impairment by pretreatment of the selective KOR antagonist norBNI (10 mg/kg, i.p.) or KOR deletion. Then, significant increased dynorphin and KOR mRNA were observed exclusively in prelimbic cortex (PL) other than infralimbic cortex. Finally, microinjection with norBNI into PL also improved cognitive memory in METH-treated mice using NOR and spontaneous alternation behaviour test. Our results demonstrated that dynorphin/KOR system activation in PL may be a possible mechanism for METH-induced cognitive impairment and shed light on KOR antagonists as a potential neuroprotective agent against the cognitive deficits induced by drug abuse.

Revealing an initiation inhibition of RCA and its application in nucleic acid detection.

Rolling circle amplification is a widely used biosensing technique. Although various secondary structures have been employed in RCA, their effects on RCA efficiency have seldom been reported. Here, we find that stems in circular templates can strongly inhibit RCA, and the primer-stem distance is responsible for the inhibition. Based on the results, we propose an initiation inhibition mechanism and present a design principle for a general RCA assay. Inspired by this mechanism, we further propose a new nucleic acid detection method. The results verify that this method can increase RCA detection sensitivity according to the target recycling principle. Besides DNA detection, it can also achieve single mismatch discrimination of miRNA detection after optimization. This method also shows convenient visualization detection. The initiation inhibition of RCA could be helpful for RCA applications as promising detection techniques.

Research on Similarity Simulation Experiment of Mine Pressure Appearance in Surface Gully Working Face Based on BOTDA.

In order to study the mountain deflection characteristics and the pressure law of the working face after the mining of a shallow coal seam under the valley terrain, a geometric size of 5.0 × 0.2 × 1.33 m is used in the physical similarity model. Brillouin optical time domain analysis (BOTDA) technology is applied to a similar physical model experiment to monitor the internal strain of the overlying rock. In this paper, the strain law of the horizontal optical fiber at different stages of the instability of the mountain structure is analyzed. Combined with the measurement of the strain field on the surface of the model via digital image correlation (DIC) technology, the optical fiber strain characteristics of the precursor of mountain instability are given. The optical fiber characterization method of working face pressure is proposed, and the working face pressures at different mining stages in gully terrain are characterized. Finally, the relationship between the deflection instability of the mountain and the strong ground pressure on the working face is discussed. The sudden increase in the strain peak point of the horizontally distributed optical fiber strain curve can be used to distinguish the strong ground pressure. At the same time, this conclusion is verified by comparing the measured underground ground pressure values. The research results can promote the application of optical fiber sensing technology in the field of mine engineering.

Antinociceptive activities and mechanism of action of Cepharanthine.

Cepharanthine is an alkaloid that isolated from Stephania cepharantha Hayata, however，its analgesic properties are unclear and the molecular targets that mediating Cepharanthine-induced analgesia are not explored yet. In the current study, mice pain models including hot plate, acetic acid-induced writhing and formalin tests were conducted to evaluate the antinociceptive actions of Cepharanthine. [3H]-ligand competitive binding assay was applied to determine the binding affinity and selectivity of Cepharanthine at κ, µ and δ opioid receptors. Cepharanthine-induced constipation was investigated using the small intestinal transit test. The results showed that intraperitoneal injection of Cepharanthine produced potent antinociception with an ED50 value of 24.5 mg/kg in the acetic acid-induced writhing test. In the formalin test, Cepharanthine produced moderate antinociception with the maximum analgesic activity of 42.6 ± 11.3% in phase I and 60.1 ± 7.7% in phase Ⅱ, respectively. Cepharanthine had no effects in the hot plate test. In vitro radioligand binding assay, Cepharanthine exhibited a high affinity for µ opioid receptors with a Ki value of 80 nM, without binding to κ and δ opioid receptors. Correspondingly, Cepharanthine-mediated antinociceptive effects were antagonized by pretreatment with opioid receptor antagonist naloxone. Cepharanthine also decreased the small intestine propulsion rates in the small intestinal transit test. Together, this study firstly demonstrates that Cepharanthine produces potent antinociception in acetic acid-induced visceral pain and moderate antinociception in formalin-induced inflammatory pain, and its mechanism of action may be through activation of µ opioid receptors.

Alteration of twinfilin1 expression underlies opioid withdrawal-induced remodeling of actin cytoskeleton at synapses and formation of aversive memory.

Exposure to drugs of abuse induces alterations of dendritic spine morphology and density that has been proposed to be a cellular basis of long-lasting addictive memory and heavily depend on remodeling of its underlying actin cytoskeleton by the actin cytoskeleton regulators. However, the actin cytoskeleton regulators involved and the specific mechanisms whereby drugs of abuse alter their expression or function are largely unknown. Twinfilin (Twf1) is a highly conserved actin-depolymerizing factor that regulates actin dynamics in organisms from yeast to mammals. Despite abundant expression of Twf1 in mammalian brain, little is known about its importance for brain functions such as experience-dependent synaptic and behavioral plasticity. Here we show that conditioned morphine withdrawal (CMW)-induced synaptic structure and behavior plasticity depends on downregulation of Twf1 in the amygdala of rats. Genetically manipulating Twf1 expression in the amygdala bidirectionally regulates CMW-induced changes in actin polymerization, spine density and behavior. We further demonstrate that downregulation of Twf1 is due to upregulation of miR101a expression via a previously unrecognized mechanism involving CMW-induced increases in miR101a nuclear processing via phosphorylation of MeCP2 at Ser421. Our findings establish the importance of Twf1 in regulating opioid-induced synaptic and behavioral plasticity and demonstrate its value as a potential therapeutic target for the treatment of opioid addiction.

Differences in service and antibiotics use following symptomatic respiratory tract infections between 2016 and 2021 in rural Anhui, China.

In the past 10-15 years, the government of China has made various efforts in tackling excessive antibiotics use. Yet, little is known about their effects at rural primary care settings. This study aimed to determine the impact of government policies and the COVID-19 pandemic on antibiotic prescribing practices at such settings utilizing data from separate studies carried out pre- and during the pandemic, in 2016 and 2021 in Anhui province, China, using identical sampling and survey approaches. Data on antibiotics prescribed, diagnosis, socio-demographic, etc., were obtained through non-participative observation and a structured exit survey. Data analysis comprised mainly descriptive comparisons of 1153 and 762 patients with respiratory infections recruited in 2016 and 2021, respectively. The overall antibiotics prescription rate decreased from 89.6% in 2016 to 69.1% in 2021, and the proportion of prescriptions for two or more classes of antibiotics was estimated as 35.9% in 2016 and 11.0% in 2021. There was a statistically significant decrease in the number of days from symptom onset to clinic visits between the year groups. In conclusion, measures to constrain excessive prescription of antibiotics have led to some improvements at the rural primary care level, and the COVID-19 pandemic has had varying effects on antibiotic use.

Amygdala dynorphin/κ opioid receptor system modulates depressive-like behavior in mice following chronic social defeat stress.

Major depression disorder is a severe and recurrent neuropsychological disorder characterized by lowered mood and social activity and cognitive impairment. Owing to unclear molecular mechanisms of depression, limited interventions are available in clinic. In this study we investigated the role of dynorphin/κ opioid receptor system in the development of depression. Mice were subjected to chronic social defeat stress for 14 days. Chronic social defeat stress induced significant social avoidance in mice characterized by decreased time duration in the interaction zone and increased time duration in the corner zone. Pre-administration of a κ opioid receptor antagonist norBNI (10 mg/kg, i.p.) could prevent the development of social avoidance induced by chronic social defeat stress. Social avoidance was not observed in κ opioid receptor knockout mice subjected to chronic social defeat stress. We further revealed that social defeat stress activated c-fos and ERK signaling in the amygdala without affecting the NAc, hippocampus and hypothalamus, and ERK activation was blocked by systemic injection of norBNI. Finally, the expression of dynorphin A, the endogenous ligand of κ opioid receptor, was significantly increased in the amygdala following social defeat stress; microinjection of norBNI into the amygdala prevented the development of depressive-like behaviors caused by social defeat stress. The present study demonstrates that upregulated dynorphin/κ opioid receptor system in the amygdala leads to the emergence of depression following chronic social defeat stress, and sheds light on κ opioid receptor antagonists as potential therapeutic agents for the prevention and treatment of depression following chronic stress.

Novel selective κ agonists SLL-039 and SLL-1206 produce potent antinociception with fewer sedation and aversion.

SLL-039 (N-cyclopropylmethyl-7α-4'-(N'-benzoyl) amino-phenyl-6,14-endoethano-tetrahydronorthebaine) and SLL-1206 (N-cyclopropylmethyl-7α-3'-(p-methoxybenzyl) amino-phenyl-6,14-endoethano-tetrahydronorthebaine) are two 4,5-epoxymorphinan-based high selective κ receptor agonists that we recently discovered. In the present study we characterized their pharmacological properties in comparison with arylacetamide-based typical κ agonist U50,488H. We showed that both SLL-039 and SLL-1206 produced potent and long-lasting antinociceptive actions in three different rodent models of pain via activation of κ opioid receptor. In hot-plate assay, the antinociceptive potency of SLL-039 and SLL-1206 increased about 11-and 17.3-fold compared to U50,488H and morphine, respectively, with ED50 values of 0.4 mg/kg. Following repeated administration, SLL-1206, SLL-039, and U50,488H all developed analgesic tolerance tested in hot-plate assay. U50,488H and SLL-039 produced antipruritic effects in a dose-dependent manner, whereas SLL-1206 displayed some antipruritic effects only at very low doses. In addition, SLL-1206 was capable of decreasing morphine-induced physical dependence. More importantly, SLL-039 and SLL-1206 at effective analgesic doses did not cause sedation and conditioned place aversion (CPA), whereas U50,488H did. In comparison with SLL-039, SLL-1206 caused similar antinociceptive responses, but fewer sedation and CPA. In conclusion, our results suggest that SLL-039 and SLL-1206 have potential to be developed as novel analgesic agents, and 4,5-expoxymorphinan scaffold is an attractive structure for the development of selective κ agonists with fewer side effects.

Study on Quantitative Characterization of Coupling Effect between Mining-Induced Coal-Rock Mass and Optical Fiber Sensing.

The monitoring of mine pressure, division of vertical zoning of the overburden, discrimination of key stratum structure of the overburden and monitoring of advanced abutment pressure are still the main research problems in the field of coal mining. Therefore, the promotion of development of a monitoring technology of mining-induced rock mass deformation has important research value in the mining field. There are many problems to be solved in the application of optical fiber sensing (OFS) to deformation monitoring, such as the corresponding relationship between actual deformation and optical parameters, the coupling relationship between the optical fiber and rock mass and the reasonable division of vertical zoning of the overburden. In this study, a quantitative index of coupling action between the mining rock mass and optical fiber is put forward, and the coupling coefficient of different vertical zonings is quantitatively analyzed and discussed. Based on this, five different media in contact with optical fiber are proposed. The relationship between the strain curve form, the development height of the fracture zone and the activity of key stratum is established. It is of great academic value and research significance to establish a characterization system of displacement, deformation and structural evolution of overlying strata based on optical fiber sensing technology.

Application of l-Threonine Aldolase to on-DNA Reactions.

Enzymatic catalysis is a highly attractive approach to the DNA encoded library technology (DEL) that has not been widely explored. In this paper, we report an l-threonine aldolase (l-TA)-catalyzed on-DNA aldol reaction to form ß-hydroxy-α-amino acids, and its diastereoselectivity determination. l-TAs from three species show good on-DNA aldehyde scope and complementary stereoselectivity. The formed aldol product can be further diversified via various reactions, which demonstrates the utility of this reaction in DEL.

Clinical diagnosis and treatment of common respiratory tract infections in relation to microbiological profiles in rural health facilities in China: implications for antibiotic stewardship.

BACKGROUND: This paper tries to describe prevalence and patterns of antibiotics prescription and bacteria detection and sensitivity to antibiotics in rural China and implications for future antibiotic stewardship. METHODS: The study was implemented in one village clinic and one township health center in each of four rural residential areas in Anhui Province, China. It used mixed-methods comprising non-participative observations, exit-survey and microbiological study. Observations were conducted to record clinical diagnosis and antibiotic prescription. Semi-structured questionnaire survey was used to collect patient's sociodemographic information and symptoms. Sputum and throat swabs were collected for bacterial culture and susceptibility testing. RESULTS: A total of 1068 (51.0% male vs 49.0% female) patients completed the study with diagnosis of respiratory tract infection (326,30.5%), bronchitis/tracheitis (249,23.3%), pharyngitis (119,11.1%) and others (374, 35.0%). They provided 683 sputum and 385 throat swab specimens. Antibiotics were prescribed for 88% of the RTI patients. Of all the specimens tested, 329 (31%) were isolated with bacteria. The most frequently detected bacteria were K. pneumonia (24% in all specimens), H. influenza (16%), H. parainfluenzae (15%), P. aeruginosa (6%), S.aureus (5%), M. catarrhalis (3%) and S. pneumoniae (2%). CONCLUSIONS: The study establishes the feasibility of conducting microbiological testing outside Tier 2 and 3 hospitals in rural China. It reveals that prescription of antibiotics, especially broad-spectrum and combined antibiotics, is still very common and there is a clear need for stewardship programs aimed at both reducing the number of prescriptions and promoting single and narrow-spectrum antibiotics.

Mine MIMO Depth Receiver: An Intelligent Receiving Model Based on Densely Connected Convolutional Networks.

Multiple-input multiple-output (MIMO) systems suffer from high BER in the mining environment. In this paper, the mine MIMO depth receiver model is proposed. The model uses densely connected convolutional networks for feature extraction and constructs multiple binary classifiers to recover the original information. Compared with conventional MIMO receivers, the model has no error accumulation caused by processes such as decoding and demodulation. The experimental results show that the model has better performance than conventional decoding methods under different modulation codes and variations in the number of transmitting terminals. Furthermore, we demonstrate that the model can still achieve effective decoding and recover the original information with some data loss at the receiver.

Investigation of Deformation Pattern and Movement Law of the Huge-Thick Conglomerate Stratum by a Large-Scale 3D Model Test with Distributed Optical Fiber Sensor Monitoring.

Mining activities under the circumstances of huge-thick stratum occurrence commonly result in dynamic response of the working face. It is crucial to understand the rock failure and movement of the huge-thick stratum in order to prevent dynamic hazards. This paper introduces distributed optical fiber sensor (DOFS) monitoring into a large-scale model test to investigate the deformation pattern and movement law of the huge-thick conglomerate (HTC); the monitoring results are verified by numerical simulation. The results indicate that DOFS monitoring captures the spatiotemporal evolution of zoning development in the overburden deformation. The deformation field of HTC is illustrated, and there exists a strain basin that can be used to estimate the movement law of HTC. The average strain variability Ex, a new homogenization index for characterizing the overburden deformation, is proposed to describe the broken rules of the HTC. The numerical simulation proves the feasibility of the DOFS monitoring method and the correctness of the deformation pattern and movement law. This study provides efficient methods for DOFS monitoring utilization to investigate mining engineering problems and could be beneficial for unearthing the mechanisms of deep ground rock deformation.