Nutritional changes in trees during drought-induced mortality: A comprehensive meta-analysis and a field study.

Both macronutrients and micronutrients are essential for tree growth and development through participating in various ecophysiological processes. However, the impact of the nutritional status of trees on their ability to withstand drought-induced mortality remains inconclusive. We thus conducted a comprehensive meta-analysis, compiling data on 11 essential nutrients from 44 publications (493 independent observations). Additionally, a field study was conducted on Pinus sylvestris L. trees with varying drought-induced vitality loss in the "Visp" forest in southern Switzerland. No consistent decline in tree nutritional status was observed during tree mortality. The meta-analysis revealed significantly lower leaf potassium (K), iron (Fe), and copper (Cu) concentrations with tree mortality. However, the field study showed no causal relationships between nutritional levels and the vitality status of trees. This discrepancy is mainly attributed to the intrinsic differences in the two types of experimental designs and the ontogenetic stages of target trees. Nutrient reductions preceding tree mortality were predominantly observed in non-field conditions, where the study was conducted on seedlings and saplings with underdeveloped root systems. It limits the nutrient uptake capacity of these young trees during drought. Furthermore, tree nutritional responses are also influenced by many variables. Specifically, (a) leaf nutrients are more susceptible to drought stress than other organs; (b) reduced tree nutrient concentrations are more prevalent in evergreen species during drought-induced mortality; (c) of all biomes, Mediterranean forests are most vulnerable to drought-induced nutrient deficiencies; (d) soil types affect the direction and extent of tree nutritional responses. We identified factors that influence the relationship between tree nutritional status and drought survival, and proposed potential early-warning indicators of impending tree mortality, for example, decreased K concentrations with declining vitality. These findings contribute to our understanding of tree responses to drought and provide practical implications for forest management strategies in the context of global change.

Simulation Analysis of Firefighter Training Postures with Loads / 医用生物力学

Objective To study the injury risk and fatigue status of firefighters with different training postures under load-bearing conditions to reduce the occurrence of physical injuries and occupational diseases.Methods First,a questionnaire was administered to investigate the training injury conditions of firefighters in a fire-rescue brigade.Considering the exercise fatigue factor,which accounts for the highest proportion of injury causes,lower back analysis,static strength analysis,fatigue analysis,comfort analysis,and other human factor analysis tools in Jack software were used to analyze four common firefighter water-shooting training postures.Training postures while climbing a five-storey building with loads and a hooked ladder were also simulated.Results Injury caused by exercise fatigue accounted for 69.8%of injuries and was the most important injury-causing factor.The risk of knee and ankle joint injuries increased in all four water-shooting postures.The comfort levels of the four water-shooting postures from high to low were shoulder,standing,kneeling,and lying postures.For the entire dynamic training process,while climbing the five-storey building with loads and climbing the hooked ladder,firefighters did not have an increased risk of lower back injury but had an increased risk of ankle and knee joint injuries.Conclusions Some training postures are uncomfortable for firefighters,and they experience body discomfort during firefighting training with loads,thereby increasing injury risk.These results provide scientific references for the prevention and reduction of firefighter training injuries,and the formulation of reasonable training plans and targeted protective measures.

Methcathinone Increases Visually-evoked Neuronal Activity and Enhances Sensory Processing Efficiency in Mice / 神经科学通报·英文版

Methcathinone (MCAT) belongs to the designer drugs called synthetic cathinones, which are abused worldwide for recreational purposes. It has strong stimulant effects, including enhanced euphoria, sensation, alertness, and empathy. However, little is known about how MCAT modulates neuronal activity in vivo. Here, we evaluated the effect of MCAT on neuronal activity with a series of functional approaches. C-Fos immunostaining showed that MCAT increased the number of activated neurons by 6-fold, especially in sensory and motor cortices, striatum, and midbrain motor nuclei. In vivo single-unit recording and two-photon Ca2+ imaging revealed that a large proportion of neurons increased spiking activity upon MCAT administration. Notably, MCAT induced a strong de-correlation of population activity and increased trial-to-trial reliability, specifically during a natural movie stimulus. It improved the information-processing efficiency by enhancing the single-neuron coding capacity, suggesting a cortical network mechanism of the enhanced perception produced by psychoactive stimulants.

[Changes of non-structural carbohydrates and nitrogen contents of needles and twigs in Pinus sylvestris var. mongolica plantations along an aridity gradient]. / 沿干旱梯度樟子松人工林针叶和枝条非结构性碳水化合物及氮含量的变化.

With six Pinus sylvestris var. mongolica plantations (Huinan, Xifeng, Fujia, Zhanggutai, Naiman and Wulanaodu) along an aridity gradient in the Horqin sandy land, we examined the changes in non-structural carbohydrates (NSCs) and nitrogen (N) contents of current and one-year-old needles and twigs, to explore the carbon supply and demand status as well as the nutrient accumulation strategies of P. sylvestris var. mongolica under drought. The results showed that the contents of NSCs and soluble sugars in needles and twigs of P. sylvestris var. mongolica plantations significantly decreased with increasing aridity. From the most humid site (Huinan) to the most aridity site (Wulanaodu), the soluble sugar contents in current and one-year old needles of P. sylvestris var. mongolica decreased from 12.8% and 12.5% to 9.0% and 9.5%, respectively. The soluble sugar contents in current-year old twigs decreased from 15.6% to 9.2%. With increasing aridity, the starch contents in needles and twigs remained relatively stable, soluble sugars/starch ratio in current and one-year old needles decreased, the N contents in current and one-year old twigs significantly increased. The P. sylvestris var. mongolica plantations in the Horqin sandy land consumed soluble sugar storage under drought, resulting in a risk of mortality from 'carbon starvation'. P. sylvestris var. mongolica tended to maintain stable starch storage and accumulate N in twigs to cope with long-term drought stress.

Establishment of a candidate reference method for angiotensin Ⅱ in human plasma / 中华检验医学杂志

Objective:To establish a candidate reference method for the determination of angiotensin Ⅱ in human plasma by isotope dilution liquid chromatography tandem mass spectrometry (ID-LC-MS/MS) and to evaluate its performance.Methods:Using [ 13C 6- 15N]-angiotensin Ⅱ as the internal standard, the plasma was accurately weighed by gravimetric method and mixed with a certain amount of internal standard. At the same time, enzyme inhibitor was added. After zinc sulfate solution protein precipitation and reversed-phase solid-phase extraction plate treatment, it was analyzed by liquid chromatography tandem mass spectrometry. The multi reaction ion monitoring mode(MRM)was selected by mass spectrometry to detect specific ion fragments of angiotensin Ⅱ and internal standard. The linearity, sensitivity, precision, recovery rate and uncertainty of the performance of the established method were evaluated according to ISO15193. Results:Angiotensin Ⅱ had good linearity in the range of 10-1 000 pg/g ( r=0.999 5), the lower limit of quantification was 7.68 pg/g, the analytical recoveries were 97.14% to 102.85%, intra-batch imprecision≤3.21%, inter-batch imprecision≤2.96%, and total imprecision≤3.67%. Conclusion:A method for the determination of plasma angiotensin Ⅱ was established by ID-LC-MS/MS. The method is accurate and reliable, and is expected to be a reference method for the determination of plasma angiotensin Ⅱ.

Isolation and identification of attractants from the pupae of three lepidopteran species for the parasitoid Chouioia cunea Yang.

BACKGROUND: Chouioia cunea Yang (Hymenoptera: Eulophidae) is a parasitic wasp and natural enemy of several lepidopteran pests during their pupal stage. The volatiles from pupae of three hosts, Hyphantria cunea (Arctiidae), Antheraea pernyi (Saturniidae) and Lymantria dispar (Erebidae), were analyzed and compared to elucidate the chemical cues used by C. cunea to locate its hosts. RESULTS: The attraction of C. cunea to H. cunea pupae has no obvious association with the types of plant leaves consumed by H. cunea before pupation. C. cunea exhibited the strongest attraction to the pupae of H. cunea, followed by those of A. pernyi and L. dispar based on behavioral experiments. Gas chromatography-mass spectrometry and GC-electroantennography (GC-EAD) analyses showed that these three host pupae consisted of essentially the same active volatile components but at different relative amounts. Active components derived from these pupae by GC-EAD were alkanes from C12 to C27, and C. cunea showed different levels of attraction to different single compounds. CONCLUSION: Host location by C. cunea primarily depends on common compounds emanating from the pupae of several host species. The relative amount of each component varies across host species, guiding host preferences by C. cunea. Optimal blends of several components were identified. Understanding the chemical cues used by C. cunea to locate its host could increase the possibility of developing attractants for parasitic wasps and subsequently increasing the parasitism rate of C. cunea on various hosts. © 2019 Society of Chemical Industry.

CiteSpace-based Document Information Visualization of Literature Published by Journal of Forensic Medicine from 1985 to 2018 / 法医学杂志

Objective To analyze a knowledge web of the literature published by Journal of Forensic Medicine from its founding in 1985 to 2018, describe the evolving process of forensic science research and explore the research hotspots and frontiers at present. Methods The literature that was published by Journal of Forensic Medicine from 1985 to 2018 was collected and analyzed in terms of elements, such as emerging research hotspots, high frequency keywords, authors, dispatching units, location of institution and funding, by CiteSpace5.3 information visualization analysis software. Results All disciplines of forensic medicine were continually developing and maturing, and the publication volume of the literature on forensic pathology had the highest weight; in research hotspots, the two categories, research and identification each had their own emphasis; as the main source of contributions to the journal, research institutes accounted for 38.99% of the total number of publications; Shanghai ranked first among all regions with 1 046 articles published. The number of funded articles was generally on the rise, with the number of funded articles published largest in 2015. Conclusion As an authoritative academic journal in the field of forensic science in China, Journal of Forensic Medicine carries the development of forensic science and witnesses the institutional reform of universities and colleges, and offers a wide range of communication and cooperation in terms of technicality and application. Many scholars and scientific research institutions have gained progress continually in various research directions in the form of teamwork; and emerging research hotspots will continue to play a huge role in future practical applications.

Research Status of New Designer Drug Methcathinone in Forensic Toxicology / 法医学杂志

Methcathinone, a new cathinone designer drug, which is structurally similar to amphetamine analogs, is a central nervous stimulant.Recently, there has been a worldwide rise in its popularity and abuse, and a growing number of cases with disability or even death is reported in several countries, resulting in public concern.The typical symptoms include accelerated heartbeat, high temperature, anxiety, depression, etc.Forensic studies on its toxicity mechanism are rare.This article reviews its toxicological effects, poisoning symptoms, poisoning and addiction mechanisms, and detection methods, to provide theoretical reference for future studies and guidance for related forensic identification.

Study on DNA molecular identification of mix samples of five species of Baitouweng medicinal materials based on high-throughput sequencing technology / 药学学报

Traditional Chinese medicine Baitouweng have a long history of application. The pharmacopoeia included dry roots of Pulsatilla chinensis (Bge.) Regel of Ranunculaceae. There are easily confused species in the market circulation, such as P. cernua (Thunb.) Bercht. et Opiz., P. dahurica (Fisch.) Spreng., P. turczaninovii Kryl. et Serg., and P. chinensis (Bge.) Regel var. kissii (Mandl) S. H. Li et Y. H. Huang, etc. In this study, using the method of metagenomics, based on high-throughput sequencing technology, the ITS2 sequence of mixed samples of five species of Baitouweng medicinal materials was sequenced. First, the total DNA extraction of medicinal materials mixing powder, and the ITS2 fragment of total DNA was amplified by PCR. Second, the Illumina MiSeq platform was used to carry out Paired-end sequencing for DNA fragments. Last, using FLASH, QⅡME and GraPhlAn software to arrange and analyze, and clustering analysis with the sequences of uploaded to GenBank by our group in the early stage. The results showed that a total of 53 024 sequences of ITS2 were obtained from the mixed samples, there are 52 295 effective sequences, there are a total of 49 079 of five species of medicinal materials of P. Miller. After the representative sequences and the sequence of uploaded to GenBank by our group in the early stage were clustering analysis, 5 species of Baitouweng medicinal materials were clustered into one branch separately, presenting monophyletic. The results showed that using the high-throughput sequencing technology, using ITS2 sequence as DNA barcode, the mix powder of 5 species of Baitouweng medicinal materials could be effectively identified. It provides a new method and thought for the origin identification of mixed Chinese medicinal materials.

Study on high throughput sequencing identification of Fructus Arctii and five counterfeit species mix power / 中国中药杂志

Fructus Arctii is a traditional Chinese medicine. The main counterfeit species are the seeds of Arctium tomentosum, Onopordum acanthium, Silybum marianum, Saussurea costus, Amorpha fruticosa. Traditional identification methods or molecular barcoding techniques can identify Fructus Arctii and its counterfeit species. However, the identification of the mixture of it and its spurious species is rarely reported. In this paper, we sequenced the ITS2 sequences of Fructus Arctii and 5 kinds of spurious species mix powder by high-throughput sequencing to identify the mixed powder species and providing new ideas for the identification of Fructus Arctii mix powder. The total DNA in mixed powder was extracted, and the ITS2 sequences in total DNA was amplified. Paired-end sequencing was performed on the DNA fragment of the community using the Illumina MiSeq platform. The sequence was analyzed by the software FLASH, QIIME and GraPhlAn etc. The results showed that the high quality ITS2 sequences of 39910 mix samples were obtained from the mixed samples, of which the total ITS2 sequence of the samples genus was 34 935. Phylogenetic analysis showed that the samples contained Fructus Arctii, A. tomentosum, O. acanthium, S. marianum, S. costus and A. fruticosa. Using ITS2 sequences as DNA barcodes, high-throughput sequencing technology can be used to detect the Fructus Arctii and its spurious specie in mixed powder, which can provide reference for the quality control, safe use of medicinal materials of Fructus Arctii and the identification of mixed powder of traditional Chinese medicine.

Research progress of aptamer drugs for targeted therapy / 医学研究生学报

Aptamers,screened by the in vitro process known as Systematic Evolution of Ligands by Exponential Enrichment (SELEX),are single stranded DNA/RNA oligonucleotides that can be folded into three dimensional spatialstructure. They can specif-ically recognize the molecular markers on the cell surface. Compared with monoclonal antibodies,aptamers possess similar or even su-perior characteristics,such as high specificity and affinity,easy for modification,excellet chemical stability,non-toxicity and low im-munogenicity. Due to these advantages,aptamers are emerging as a promising tool to targeted delivery of therapeutic drugs into cells,with low toxicity and high efficacy. They can not only be used as therapeutic agent,specific drug carrier,to deliver such as drugs,nan-oparticles,nucleic acids to targeted cells. This review discusses recent advances of aptamers applied for targeted therapy.

Oncocytic variant of medullary thyroid carcinoma: 3 cases report with review of literatures / 临床与实验病理学杂志

Purpose To investigate the clinicopathologic features and differential diagnosis of oncocytic variant of medullary thyroid carcinoma (MTC).Methods Morphological,immunohistochemical findings on 3 oncocytic variant of MTC cases and electron microscopic findings on 2 of these 3 cases were studied,with review of the relevant literatures.Results The cytoplasm was abundant,eosinophilic and granular with defined margins.The nuclei were enlarged,round to oval.Prominent nucleoli were identified in some cells.Tumor cells formed sheets,trabeculae or follicles with infiltrative pattern.Immunohistochemically,thyroglobulin (TG) was negative in all 3 cases.Calcitonin was positive in 2 cases and negative in 1 case.Ultrastructurally,a large number of mitochondria and various neuroendocrine granules were found in the 2nd and 3rd cases.Conclusion Oncocytic variant of MTC is very rare with variable histopathologic appearances.It should be considered in diagnosing oncocytic lesions of thyroid.A definite diagnosis can be rendered based on comprehensive findings of the immunohistochemistry,serology study and electron microscopy.It needs to avoid misdiagnosis and missed diagnosis.

Mapping the ecological dimensions and potential distributions of endangered relic shrubs in western Ordos biodiversity center.

Potential distributions of endemic relic shrubs in western Ordos were poorly mapped, which hindered our implementation of proper conservation. Here we investigated the applicability of ecological niche modeling for endangered relic shrubs to detect areas of priority for biodiversity conservation and analyze differences in ecological niche spaces used by relic shrubs. We applied ordination and niche modeling techniques to assess main environmental drivers of five endemic relic shrubs in western Ordos, namely, Ammopiptanthus mongolicus, Amygdalus mongolica, Helianthemum songaricum, Potaninia mongolica, and Tetraena mongolica. We calculated niche overlap metrics in gridded environmental spaces and compared geographical projections of ecological niches to determine similarities and differences of niches occupied by relic shrubs. All studied taxa presented different responses to environmental factors, which resulted in a unique combination of niche conditions. Precipitation availability and soil quality characteristics play important roles in the distributions of most shrubs. Each relic shrub is constrained by a unique set of environmental conditions, the distribution of one species cannot be implied by the distribution of another, highlighting the inadequacy of one-fits-all type of conservation measure. Our stacked habitat suitability maps revealed regions around Yellow River, which are highly suitable for most species, thereby providing high conservation value.

Value and prospects of constructing digital slides data of forensic medicine / 中华医学教育探索杂志

As a rising histological specimen carrier,digital slide has advantages of easy search and fast browse.By digital scanning and stitching of traditional slides and uploading traditional slides as well as pathological information to network servers,the construction of digital slides data can take its own superiority to assist forensic medicine teaching.Combined with our research and teaching experience,this article discussed the application prospects of digital slide technology and digital slides data so as to provide references for the improvement and reformation of forensic medicine education.

A single nucleotide polymorphism in the matrix metalloproteinase 2 promoter is closely associated with high risk of nasopharyngeal carcinoma in Cantonese from southern China / 癌症

Matrix metalloproteinase 2 (MMP2) has been shown to play an important role in several steps of cancer development. The -1306C/T polymorphism of the MMP2 gene displays a strikingly lower promoter activity than the T allele, and the CC genotype in the MMP2 promoter has been reported to associate with the development of several cancers. To assess the contribution of the MMP2 -1306C/T polymorphism to the risk of nasopharyngeal carcinoma (NPC), we conducted a case-control study and analyzed MMP2 genotypes in 370 patients with NPC and 390 frequency-matched controls using real-time PCR-based TaqMan allele analysis. We found that subjects with the CC genotype had an increased risk (OR = 1.55, 95% CI = 1.05-2.27) of developing NPC compared to those with the CT or TT genotypes. Furthermore, we found that the risk of NPC was markedly increased in subjects who were smokers (OR = 15.04, 95% CI = 6.65-33.99), heavy smokers who smoked ≥ 20 pack-years (OR = 18.66, 95% CI = 7.67-45.38), or young (<60 years) at diagnosis (OR = 1.52, 95% CI = 1.01-2.29). Our results provide molecular epidemiological evidence that the MMP2 -1306C/T promoter polymorphism is associated with NPC risk, and this association is especially noteworthy in heavy smokers.

Comparative analysis of 607 autopsy cases of poisoning death / 法医学杂志

OBJECTIVE@#To provide references for forensic expertise by investigating the kinds of toxicant, routes of exposure and manners of poisoning deaths, etc.@*METHODS@#Six hundred and seven autopsy cases of poisoning deaths from 1957 to 2008 in Department of Forensic Medicine, Tongji Medical College (Tongji Forensic Science Identification Center of Hubei), were comparatively reviewed.@*RESULTS@#In 218 cases from 1999 to 2008, more than 50% of decedents were male in the ages of 30-49. The toxicants are usually taken orally and the most common manner of death was accidental. The common substances involved in poisoning death were rodenticide, poisoning gas and insecticide. Compared to the data of 1983-1998 and 1957-1982, the common toxic agents had changed significantly. The number of cases involving insecticide and cyanide poisoning decreased in recent years, and the number of cases of rodenticide, poisoning gas, alcohols poisoning displayed an increase tendency, especially for drugs abuse.@*CONCLUSION@#Poisoning deaths of pesticides remain a major public health problem for a long time and the awareness of prevention need to be raised, especially for the prevention of deaths from multiple poisons.

Image analysis on corneal opacity: A novel method to estimate postmortem interval in rabbits / 华中科技大学学报（医学）（英德文版）

Corneal opacity is one of the most commonly used parameters for estimating postmortem interval (PMI). This paper proposes a new method to study the relationship between changes of corneal opacity and PMI by processing and analyzing cornea images. Corneal regions were extracted from images of rabbits' eyes and described by color-based and texture-based features, which could represent the changes of cornea at different PMI. A KNN classifier was used to reveal the association of image features and PMI. The result of the classification showed that the new method was reliable and effective.

Characterization of protein in old myocardial infarction by FTIR micro-spectroscopy / 华中科技大学学报（医学）（英德文版）

The aim of the present study was to assess whether Fourier transform infrared spectrometry (FTIR) micro-spectroscopy could produce distinct spectral information on protein of old myocardial infarction (OMI) and to set them as molecular markers to diagnose atypical OMI. Paraffin-embedded heart samples were derived from victims dying of OMI. In combination with histological stain, FTIR and infrared micro-spectroscopy, the characteristics of OMI were analyzed morphologically and molecularly. The most relevant bands identified were the amide A, B, I and, II showing crucial spectral differences between apparent normal region and OMI region, including the peak position blue shift and the increased intensity of OMI, moreover relative increase in alpha-helix and decrease in beta-sheet of protein secondary structures in OMI. Comparing to single spectral band, the I1650/I1550 ratio was increased and rationally used as a molecular marker for diagnosing OMI. These novel preliminary findings supported further exploration of FTIR molecular profiling in clinical or forensic study, and were in accordance with histopathology.

Distribution of tramadol in acute poisoned rats / 法医学杂志

OBJECTIVE@#To develop a rapid and accurate gas chromatography method and investigate the distribution of tramadol in acute poisoned rats for information of samples selection and results evaluation in forensic identification.@*METHODS@#After an oral administration of tramadol at 1140 mg/kg (5 x LD50), concentrations of tramadol in rats' biological fluids and tissues were determined by gas chromatography.@*RESULTS@#The limit of detection of tramadol in blood and urine was 0.1 microg/mL and the limit of detection in liver was 0.1 microg/g. The intra-day precision and inter-day precision were within 3.1% and 5.5% respectively, and the recovery of tramadol in blood was more than 98%. The average levels of tramadol displayed in descending order of heart blood, liver, peripheral blood, urine, vitreous humor, kidney, lung, spleen, heart, brain respectively.@*CONCLUSION@#The established method could meet the requirements for toxicological analysis, and the results of the study suggest that blood, urine, liver, lung and kidney are suitable samples for forensic toxicological analysis in tramadol poisoning cases.

[Effects of land use/cover change on runoff sediment discharge in typical watershed in Loess gullied-hilly region of China].

By using the measurement technique of dynamic hydrological process and the estimation method of landscape ecology, this paper studied the effects of 1986-2004 land use/cover change (LUCC) on the runoff sediment discharge in the Luoyugou watershed in Tianshui of Gansu Province in third sub-region of Loess Plateau. The results showed that the LUCC in Luoyugou watershed had significant effects on the annual sediment yield. In 1995-2004, the sediment discharge was reduced by approximately 63.0%, compared with that in 1986-1994, and the reduction effect was more significant with increasing annual precipitation. The effects of LUCC on sediment discharge demonstrated seasonal fluctuation characteristic. Relative to that in 1986-1994, the reduction effect of sediment discharge in 1995-2004 was more concentrated in the period from May to October, and, the more the monthly precipitation, the more the reduction of monthly average sediment discharge in 1995-2004 than in 1986-1994. The analysis on precipitation and flood peak discharge frequency indicated that under the same frequency distribution of precipitation intensity, the average sediment concentration in any recurrence period in Luoyugou watershed was smaller in 1995-2004 than in 1986-1994.