Preparation of high-purity fluorite and nanoscale calcium carbonate from low-grade fluorite

Flotation separation of calcite from fluorite is a challenge on low-grade fluorite flotation that limits the recovery and purity of fluorite concentrate.A new acid leaching–flotation process for fluorite is proposed in this work.This innovative process raised the fluor-ite’s grade to 97.26wt%while producing nanoscale calcium carbonate from its leachate,which contained plenty of calcium ions.On the production of nanoscale calcium carbonate,the impacts of concentration,temperature,and titration rate were examined.By modifying the process conditions and utilizing crystal conditioning agents,calcite-type and amorphous calcium carbonates with corresponding particle sizes of 1.823 and 1.511μm were produced.The influence of the impurity ions Mn^(2+),Mg^(2+),and Fe^(3+)was demonstrated to reduce the particle size of nanoscale calcium carbonate and make crystal shape easier to manage in the fluorite leach solution system compared with the calcium chloride solution.The combination of the acid leaching–flotation process and the nanoscale calcium carbonate preparation method improved the grade of fluorite while recovering calcite resources,thus presenting a novel idea for the effective and clean usage of low-quality fluorite resources with embedded microfine particles.

肺癌患者阿片类药物应用现状与合理性分析:单中心回顾性研究

背景与目的癌痛严重影响患者体力活动、心理状态以及生活质量,甚至缩短患者生存时间,合理规范应用阿片类药物可有效控制癌痛。肺癌患者癌痛发病率高,需分析肺癌患者阿片类药物应用现状,以评估肺癌患者阿片类药物应用的合理性。方法回顾性分析2018年6月-2019年6月北京协和医院呼吸与危重症医学科肺癌住院患者的临床资料,分析305例应用阿片类药物的肺癌癌痛患者的临床信息和用药信息。结果应用阿片类药物的肺癌患者影响因素分析中,年龄与阿片药物应用种类为主要影响因素。男性比例高于女性,且男性患者应用阿片药物种类多、年龄多集中在60岁-69岁之间。我院肺癌患者应用阿片类药物品种和结构符合要求,用药频率最高的为羟考酮缓释片,限定日费用(defined daily cost,DDC)排名第一位同时序号比为1,同步性好。吗啡片和吗啡注射液用量低,肺癌患者整体爆发痛(breakthrough cancer pain,BTcP)控制良好。阿片类药物整体应用合理(93.4%),不合理项目主要为爆发痛处置和用药频率不合理以及超剂量问题。结论应用阿片类药物的肺癌癌痛患者多为男性,老年男性癌痛更难于控制,需要加强关注。我院肺癌患者阿片类药物整体应用合理,但仍需关注BTcP处置、阿片类药物用药剂量和特殊人群用药等问题。

抗肿瘤药物警戒研究进展

2019年我国新修订的《药品管理法》首次提出国家建立药物警戒制度,2021年我国首部《药物警戒质量管理规范》发布。药物警戒的提出和实施在我国为初始阶段,从体制、监测机制、数据库建设等方面需不断完善。我国肿瘤患者新发病例数量位居全球首位,近年来,新型抗肿瘤药物上市速度加快,临床试验繁多,抗肿瘤药物警戒工作势在必行。本文从药物警戒起源、临床实践目标、流程与方法、抗肿瘤药物警戒难点及我国药物警戒现行特点等方面归纳总结,旨在为抗肿瘤药物警戒的开展提供参考。

Alfalfa-containing diets alter luminal microbiota structure and short chain fatty acid sensing in the caecal mucosa of pigs

Background: Pork produced by outdoor-reared pigs raised mostly on alfalfa pastures attracts increasing population of consumer from most of the world. In China, pigs were raised with alfalfa-containing diets to seek for good quality pork.However, the influence of dietary alfalfa involving high level of insoluble dietary fiber(IDF) on pig intestinal luminal microbiota composition remains unclear. The objective of this study was to investigate the effects of alfalfa on luminal microbiota and short chain fatty acids(SCFA) production, and gene expressions involved in SCFA sensing, transporting and absorbing in pig caecal mucosa.Results: Twenty-four growing pigs were randomly allotted to four diets containing 0%, 5%, 10% and 15% alfalfa meal for a 28-d experiment. Ingestion of alfalfa meal-contained diets significantly increased the ratio of body weight gain to feed consumption. Illumina MiS eq sequencing of the V3 region of the 16 S r RNA genes showed that alfalfa-containing diet significantly decreased the relative abundance of genera Turicibacter, Acidiphilium, Paracoccus, Propionibacterium,Corynebacterium, Pseudomonas, Acinetobacter, and Staphylococcus, and increased the relative abundance of genera Lachnospira, Marvinbryantia, and Desulfovibrio in the caecal digesta. Butyrate concentration was significantly increased in the hindgut by the supplementation of alfalfa meal in diets. The m RNA gene expressions of FFAR3, SMCT1, MCT1,PYY, and GCG were significantly increased in the caecal mucosa of pigs fed alfalfa meal.Conclusions: Our results suggested that alfalfa-containing diet has exerted significant impacts on caecal microbiota composition, butyrate concentration and significantly upregulated m RNA expression of host caecal mucosal genes involved in SCFA sensing and absorption as well as regulation of satiety.

Selenium deficiency induces spleen pathological changes in pigs by decreasing selenoprotein expression,evoking oxidative stress,and activating inflammation and apoptosis

Background:The immune system is one aspect of health that is affected by dietary selenium(Se)levels and selenoprotein expression.Spleen is an important immune organ of the body,which is directly involved in cellular immunity.However,there are limited reports on Se levels and spleen health.Therefore,this study established a Se-deficient pig model to investigate the mechanism of Se deficiency-induced splenic pathogenesis.Methods:Twenty-four pure line castrated male Yorkshire pigs(45 days old,12.50±1.32 kg,12 full-sibling pairs)were divided into two equal groups and fed Se-deficient diet(0.007 mg Se/kg)or Se-adequate diet(0.3 mg Se/kg)for 16 weeks.At the end of the trial,blood and spleen were collected to assay for erythroid parameters,the osmotic fragility of erythrocytes,the spleen index,histology,terminal deoxynucleotidyl transferase nick-end labeling(TUNEL)staining,Se concentrations,the selenogenome,redox status,and signaling related inflammation and apoptosis.Results:Dietary Se deficiency decreased the erythroid parameters and increased the number of osmotically fragile erythrocytes(P<0.05).The spleen index did not change,but hematoxylin and eosin and TUNEL staining indicated that the white pulp decreased,the red pulp increased,and splenocyte apoptosis occurred in the Se deficient group.Se deficiency decreased the Se concentration and selenoprotein expression in the spleen(P<0.05),blocked the glutathione and thioredoxin antioxidant systems,and led to redox imbalance.Se deficiency activated the NF-κB and HIF-1αtranscription factors,thus increasing pro-inflammatory cytokines(IL-1β,IL-6,IL-8,IL-17,and TNF-α),decreasing anti-inflammatory cytokines(IL-10,IL-13,and TGF-β)and increasing expression of the downstream genes COX-2 and iNOS(P<0.05),which in turn induced inflammation.In addition,Se-deficiency induced apoptosis through the mitochondrial pathway,upregulated apoptotic genes(Caspase3,Caspase8,and Bak),and downregulated antiapoptotic genes(Bcl-2)(P<0.05)at the mRNA level,thus verifying the results of TUNEL staining.Conclusions:These results indicated that Se deficiency induces spleen injury through the regulation of selenoproteins,oxidative stress,inflammation and apoptosis.

Influences of dietary protein sources and crude protein levels on intracellular free amino acid profile in the longissimus dorsi muscle of finishing gilts

Background： The current study was carried out to determine effects of dietary protein source and crude protein（CP）level on carcass characteristics, meat quality, and muscle amino acid（AA） profile in finishing gilts. The experiment was designed as a 2 × 2 factorial arrangement with two sources of dietary proteins（cottonseed meal, CSM vs. soybean meal, SBM） and two levels of CP（12 % vs. 14 %, as-fed basis）. Seventy-two crossbred gilts（89.5 ± 0.9 kg） were allotted to one of four dietary treatments in a randomized complete block design for a period of 28 d. All diets were formulated to be isoenergetic and similar concentrations of standardized ileal digestible essential AA covering the nutrient requirements of pigs.Results： Growth, carcass characteristics and meat quality were not affected by dietary protein source nor crude protein level（P ＆gt; 0.10） except that average daily feed intake was increased by CSM diets（P = 0.03）. Gilts offered reduced protein diets had lower muscle p H45min（P 〈 0.05）. Neither dietary protein source nor crude protein level influenced N deposition. However, reduced protein diets decreased N intake, N excretion, and serum urea nitrogen content, whilst improved N efficiency（P 〈 0.01）. CSM diets increased N intake（P = 0.04）,but did not depress N efficiency. The concentrations of phenylalanine, tryptophan, cysteine and tyrosine（P 〈 0.05） of the longissimus muscle were decreased when gilts offered CSM diets, while muscle intracellular free valine concentration was increased（P = 0.03）. The gilts offered reduced protein diets had greater intracellular concentrations of free methionine, lysine, and total AA in muscle（P 〈 0.05）.Conclusion： These results suggest that CSM could replace SBM as a primary protein source in finishing pig diets in terms of performance, N efficiency, carcass characteristics, and meat quality, but decrease the concentrations of muscle specific AA. Furthermore, the reduced protein diet played an important role in increasing muscle intracellular concentrations of specific free amino acids（FAA）, and in reducing the relative ratios of specific FAA to lysine in longissimus dorsi muscle of pig, whose biological meaning needs further studies.

Potential for soil carbon sequestration under conservation agriculture in a warming climate

Agricultural soil has numerous links with climate change.It comprises a substantial part of farming systems that are affected by climate change and can significantly impact food security[1].An increase in the soil carbon(C)stock is associated with an increase in the crop yield.Moreover,agricultural soil remains a source for all three major greenhouse gases(GHGs),i.e.,carbon dioxide(CO_(2)),methane and nitrous oxide,which contributes directly to climate change.In addition,enhancing soil C sequestration in agricultural land could offset GHG emissions,promote more sustainable and climate-resilient agricultural systems.

Terrestrial carbon sinks in China and around the world and their contribution to carbon neutrality

Enhancing the terrestrial ecosystem carbon sink(referred to as terrestrial C sink) is an important way to slow down the continuous increase in atmospheric carbon dioxide(CO_(2)) concentration and to achieve carbon neutrality target.To better understand the characteristics of terrestrial C sinks and their contribution to carbon neutrality,this review summarizes major progress in terrestrial C budget researches during the past decades,clarifies spatial patterns and drivers of terrestrial C sources and sinks in China and around the world,and examines the role of terrestrial C sinks in achieving carbon neutrality target.According to recent studies,the global terrestrial C sink has been increasing from a source of (-0.2±0.9) Pg C yr^(-1)(1 Pg=1015g)in the 1960s to a sink of (1.9±1.1) Pg C yr^(-1) in the 2010s.By synthesizing the published data,we estimate terrestrial C sink of 0.20–0.25 Pg C yr^(-1) in China during the past decades,and predict it to be 0.15–0.52 Pg C yr^(-1) by 2060.The terrestrial C sinks are mainly located in the mid-and high latitudes of the Northern Hemisphere,while tropical regions act as a weak C sink or source.The C balance differs much among ecosystem types:forest is the major C sink;shrubland,wetland and farmland soil act as C sinks;and whether the grassland functions as C sink or source remains unclear.Desert might be a C sink,but the magnitude and the associated mechanisms are still controversial.Elevated atmospheric CO_(2) concentration,nitrogen deposition,climate change,and land cover change are the main drivers of terrestrial C sinks,while other factors such as fires and aerosols would also affect ecosystem C balance.The driving factors of terrestrial C sink differ among regions.Elevated CO_(2) concentration and climate change are major drivers of the C sinks in North America and Europe,while afforestation and ecological restoration are additionally important forcing factors of terrestrial C sinks in China.For future studies,we recommend the necessity for intensive and long-term ecosystem C monitoring over broad geographic scale to improve terrestrial biosphere models for accurately evaluating terrestrial C budget and its dynamics under various climate change and policy scenarios.

Mechanical properties of rock materials with related to mineralogical characteristics and grain size through experimental investigation： a comprehensive review

Mechanical properties of rock materials are related to textural characteristics. The relationships between mechanical properties and textural characteristics have been extensively investigated for differently types of rocks through experimental tests. Based on the experimental test data, single- and multiple- variant regression analyses are conducted among mechanical properties and textural characteristics. Textural characteristics of rock materials are influenced by the following factors： mineral composition, size, shape, and spatial distribution of mineral grains, porosity, and inherent microcracks. This study focuses on the first two： mineral composition and grain size. This study comprehensively summarizes the regression equations between mechanical properties and mineral content and the regression equations between mechanical properties and grain size. Further research directions are suggested at the end of this study.

Yak rumen microbiome elevates fiber degradation ability and alters rumen fermentation pattern to increase feed efficiency

Rumen microbes play an important role in ruminant energy supply and animal performance.Previous studies showed that yak(Bos grunniens)rumen microbiome and fermentation differ from other ruminants.However,little is understood about the features of the rumen microbiome that make yak adapted to their unique environmental and dietary conditions.This study was to investigate the rumen microbiome and metabolome to understand how yak adapt to the coarse forage and harsh environment in the Qinghai-Tibetan plateau.Nine female Qaidam yellow cattle(Bos taurus),9 dzomo(hybrids of cattle and yak)and 9 female plateau yak(B.grunniens),about 5 to 6 years old,were used in this study.Rumen fermentation parameters,fibrolytic enzyme activities,and rumen metataxonomic were determined.Then 18(6 samples per group)were selected for rumen metagenomic and metabolome analysis.Metataxonomic analysis revealed that the rumen microbiota was significantly different among plateau yak,Qaidam yellow cattle,and dzomo(P<0.05).Metagenomic analysis displayed a larger gene pool encoding a richer repertoire of carbohydrate-active enzymes in the rumen microbiome of plateau yak and dzomo than Qaidam yellow cattle(P<0.05).Some of the genes encoding glycoside hydrolases that mediate the digestion of cellulose and hemicellulose were significantly enriched in the rumen of plateau yak than Qaidam yellow cattle,but glycoside hydrolase 57 that primarily includes amylases was abundant in Qaidam yellow cattle(P<0.05).The rumen fermentation profile differed also,Qaidam yellow cattle having a higher molar proportion of acetate but a lower molar proportion of propionate than dzomo and plateau yak(P<0.05).Based on metabolomic analysis,rumen microbial metabolic pathways and metabolites were different.Differential metabolites are mainly amino acids,carboxylic acids,sugars,and bile acids.Changes in rumen microbial composition could explain the above results.The present study showed that the rumen microbiome of plateau yak helps its host to adapt to the Qinghai-Tibetan plateau.In particular,the plateau yak rumen microbiome has more enzymes genes involved in cellulase and hemicellulase than that of cattle,resulting higher fibrolytic enzyme activities inyak,further providing stronger fiber degradation function.

PLEK2 promotes cancer stemness and tumorigenesis of head and neck squamous cell carcinoma via the c-Myc-mediated positive feedback loop

Background:Head and neck squamous cell carcinoma(HNSCC)is one of the most frequent malignancies worldwide and is characterized by unfavorable prognosis,high lymph node metastasis and early recurrence.However,the molecular events regulating HNSCC tumorigenesis remain poorly understood.Therefore,uncovering the underlying mechanisms is urgently needed to identify novel and promising therapeutic targets for HNSCC.In this study,we aimed to explore the role of pleckstrin-2(PLEK2)in regulating HNSCC tumorigenesis.Methods:The expression pattern of PLEK2 and its clinical significance in HNSCC were determined by analyzing publicly assessable datasets and our own independent HNSCC cohort.In vitro and in vivo experiments,including cell proliferation,colony formation,Matrigel invasion,tumor sphere formation,ALDEFLUOR,Western blotting assays and xenograft mouse models,were used to investigate the role of PLEK2 in regulating the malignant behaviors of HNSCC cells.The underlying molecular mechanisms for the tumor-promoting role of PLEK2 were elucidated using co-immunoprecipitation,cycloheximide chase analysis,ubiquitination assays,chromatin immunoprecipitation-quantitative polymerase chain reaction,luciferase reporter assays and rescue experiments.Results:The expression levels of PLEK2 mRNA and protein were significantly increased in HNSCC tissues,and PLEK2 overexpression was strongly associated with poor overall survival and therapeutic resistance.Additionally,PLEK2 was important for maintaining the proliferation,invasion,epithelial-mesenchymal transition,cancer stemness and tumorigenesis of HNSCC cells and could alter the cellular metabolism of the cancer cells.Mechanistically,PLEK2 interacted with c-Myc and reduced the association of F-box and WD repeat domain containing 7(FBXW7)with c-Myc,thereby avoiding ubiquitination and subsequent proteasome-mediated degradation of c-Myc.Moreover,the c-Myc signaling activated by PLEK2 was important for sustaining the aggressive malignant phenotypes and tumorigenesis of HNSCC cells.c-Myc also directly bounded to the PLEK2 promoter and activated its transcription,forming a positive feedback loop.Conclusions:Collectively,these findings uncover a previously unknown molecular basis of PLEK2-enhanced c-Myc signaling in HNSCC,suggesting that PLEK2 may represent a promising therapeutic target for treating HNSCC.

Mapping the vertical distribution of maize roots in China in relation to climate and soil texture

Aims Optimizing water and fertilizer management for crops requires an understanding of root distribution.Maize(Zea mays L.)is currently the most widely planted cereal crop in China,yet the vertical dis-tribution of maize roots across different regions remains unknown.The aims of this work were(i)to quantify the effects of climate and soil texture on the vertical distribution of maize roots,and(ii)to show the depth distribution of root biomass in China.Methods We used data of maize root biomass from 11 Chinese ecological stations with discontinuous observations from 2004 to 2014 to fit the regression coefficientβfor an asymptotic equation Y=1-βd,where d is the soil depth and Y is the proportion of root biomass from the surface to depth d.A statistical model was then developed to quantify the effects of climate and soil texture on the fittedβval-ues.Using the statistical model,we map the depth distribution of maize root biomass in China.Important Findings Maize root biomass in the 0-100 cm soil depth varied by an order of magnitude at different stations,from 64 to 268 g m−2.Maize planted in sandy soils and/or maize with high accumu-lated temperature for development had higher root biomass and deeper rooting systems.The fittedβvalues ranged from 0.785 to 0.977,which can be modeled by an integration of the accu-mulated temperature during the maize growing period and the soil clay and sand fractions(R2=0.66,n=50,P<0.001).Up to 82%of maize planting regions in China showed shallower rooting systems where more than 90%and 95%of the root bio-mass occurred in the top 20 and 30 cm soil layers,respectively.Deeper rooting systems occurred in some temperate arid and temperate semi-arid regions,with less than 80%of the root bio-mass in the top 20 cm soil.Our findings highlighted the vertical distribution of maize roots,and underlined the spatial variability in the vertical distribution of roots across China’s planting areas of maize.

Most root-derived carbon inputs do not contribute to long-term global soil carbon storage

Plant root-derived carbon(C)inputs(I_(root))are the primary source of C in mineral bulk soil.However,a fraction of I_(root)may lose quickly(I_(loss),e.g.,via rhizosphere microbial respiration,leaching and fauna feeding)without contributing to long-term bulk soil C storage,yet this loss has never been quantified,particularly on a global scale.In this study we integrated three observational global data sets including soil radiocarbon content,allocation of photo synthetically assimilated C,and root biomass distribution in 2,034 soil profiles to quantify I_(root)and its contribution to the bulk soil C pool.We show that global average I_(root)in the 0-200 cm soil profile is 3.5 Mg ha^(-1)yr^(-1),~80%of which(i.e.,I_(loss))is lost rather than co ntributing to long-term bulk soil C storage.I_(root)decreases exponentially with soil depth,and the top 20 cm soil contains>60%of total I_(root).Actual C input contributing to long-term bulk soil storage(i.e.,I_(root)-I_(loss))shows a similar depth distribution to I_(root).We also map I_(loss)and its depth distribution across the globe.Our results demonstrate the global significance of direct C losses which limit the contribution of I_(root)to bulk soil C storage;and provide spatially explicit data to facilitate reliable soil C predictions via separating direct C losses from total root-derived C inputs.

Effects of ultrasound-assisted Fenton treatment on structure and hypolipidemic activity of apricot polysaccharides

In order to improve the hypolipidemic activity of apricot polysaccharide,the methods of modifying polysaccharide were preliminarily screened,and the modification process conditions were further optimized by response surface methodology.Subsequently,the structure characterization and hypolipidemic activity of polysaccharide obtained by ultrasound-assisted Fenton treatment(EAP-UF)were studied.The results of Box-Behnken design indicated that under the optimal conditions of ultrasound-assisted Fenton degradation,the binding rate of sodium taurocholate and sodium glycocholate were 62.10%and 59.87%,respectively.Furthermore,the molecular weight,particle size,PDI value and roughness of EAP-UF decreased obviously,while the contents of hydroxyl,carbonyl carboxyl and rhamnose increased obviously.What's more,EAP-UF could significantly reduce the content of fat accumulation,triglyceride and total cholesterol in Caenorhabditis elegans.Taken together,ultrasound-assisted Fenton treatment is an effective method to enhance the hypolipidemic activity of polysaccharides.

Differential regulation of JAK1 expression by ETS1 associated with predisposition to primary biliary cholangitis

Primary biliary cholangitis(PBC)is an autoimmune liver disease characterized by the destruction of intrahepatic small bile ducts and progressive cholestasis,eventually leading to liver cirrhosis and hepatic failure without appropriate treatment(Terziroli Beretta-Piccoli et al.,2019).