Determination of 14 Organophosphorus Pesticide Residues in Mutton by Gel Permeation Chromatography-Gas Chromatography-Mass Spectrometry(GPC-GC-MS)

[Objectives]This study was conducted to purify mutton samples by gel permeation chromatography(GPC).[Methods]Fourteen organophosphorus pesticide residues in samples were qualitatively and quantitatively analyzed by gas chromatography-mass spectrometry(GC-MS)in selective ion scanning mode(SIM).[Results]The organophosphorus pesticide standard solutions showed good linearity in the mass concentration range of 0.1-10.0μg/ml with correlation coefficients(r)not lower than 0.999,and the detection limits(S=3 N)ranged from 0.01 to 0.05 mg/kg.The average recovery values were in the range of 80.2%-99.7%,with relative standard deviations(RSDs,n=3)in the range of 1.8%-6.3%,at the addition levels of 0.5,1.0 and 2.0 mg/kg.[Conclusions]The method is simple,sensitive and accurate,and can be used for the determination of organophosphorus pesticide residues in mutton.

Sex Determination in Homo sapiens as a Multi-Step Process: Potential for Development of Variants and Sex Differences in Disease Risk

Reproduction via cis-binary mechanisms appears to have evolved fairly early in the evolution of complex organisms, and a system committed to prior to evolution of humans. While the evolution of a chromosomal-specific approach has been a successful strategy for survival of a large variety of species including humans, the fidelity of sex determination leading to 100% cis-binary outcomes is not achieved in many species, with evidence for homosexual or bisexual behaviour evident in more than 1500 species. Thus, such outcomes indicates that sex determination is a multi-step process and not a single event, and as such, could lead to the appearance of variants during the process which developed much earlier than humans. Variants could arise either due to intrinsic variation in the steps of determination, or also be influenced by environmental factors of a biological or psychological nature. In contrast to homosexual variants which do not require interventions such as hormone therapy or surgery, expression of gender dysphoria, is more based in psychology, but also has biological underpinnings and can be influenced by such hormonal interventions and surgery. While the numbers of those with gender dysphoria is small (~0.6% - 1.0% of population), the attention given to this issue raises the possibility of biological and psychological environmental factors impacting the emergence of some of those expressing gender dysphoria. Furthermore, transitioning from male-to-female or female-to-male can have consequences regarding disease risks latter in life, including the appearance of autoimmune diseases. This review will attempt to review some of the evidence regarding sex determination, discuss why the system has potentially not been improved upon during evolution, how a potential role for sex chromosome function on neurodevelopment may be central to variation in humans, and how commitment to the current strategy is likely integrated into other sex-related events such as puberty, pregnancy, and menopause to ensure species survival. It will also discuss how variants in sex determination could contribute to sex differences in disease risk and how epigenetic modifications could play a role in such risk. .

Making waste profitable: Efficient recovery of metallic iron from jarosite residues

To address the hazardous by-product of zinc smelting and resource utilization of jarosite residue,this study applies an electric field-assisted hot acid treatment to completely recycle iron(Fe).This innovative approach aims to enhance the leaching efficiency of Fe from jarosite residue.The introduction of an electric field changes the charge distribution on the surface of the particles to enhance ions and electrons exchange and promotes the collision between particles to strengthen reaction kinetics.Based on the above,the leaching efficiency of Fe in jarosite under sulfuric acid attack has improved observably.The result shows that Fe leaching efficiency reaches 98.83%,which is increased by 28%under the optimal experimental conditions:current density of 30 mA·cm^(-2),H_(2)SO_(4) concentration of 1.5 mol·L^(-1),solid-liquid ratio of 70 g·L^(-1),temperature of 80℃ and time of 12 h.Leaching kinetics calculations show that the apparent activation energy is 16.97 kJ·mol^(-1) and the leaching of jarosite residue is controlled by a mixture of chemical reaction and diffusion,as well as the temperature and concentration of the leaching solution have an influence on leaching.This work provides a feasible idea for the efficient leaching of Fe from jarosite residue.

Silencing transformer and transformer-2 in Zeugodacus cucurbitae causes defective sex determination with inviability of most pseudomales

transformer is a switch gene for sex determination in many insects, which cooperates with transformer-2 that is expressed in both sexes to regulate female differentiation, particularly in dipterans. Zeugodacus cucurbitae(Coquillett) is a very destructive pest worldwide, however, its sex determination pathway remains largely uncharacterized. Here, we show that the female sex ratio is sharply reduced with knockdown of either transformer or transformer-2 by RNA interference in early embryos of Z. cucurbitae. Most of the males grown from the embryos with transient transformer and transformer-2 suppression mated with wild-type females and produced mixed sex progeny, with one exception that produced only female progeny, and all of the few remaining males failed to mate with wild-type females and produced no progeny. The exceptional male and those males with mating failure were XX pseudomales as determined by the detection of Y chromosome-linked Maleness-on-the-Y, indicating that most XX pseudomales are not viable. The phenotypes of transformer and transformer-2 suggest that they play a key role in regulating sex determination and are required for female sexual development of Z. cucurbitae. Our results will be beneficial to the understanding of sex determination in Z. cucurbitae and can facilitate the development of genetic sexing strains for its biological control.

Relative orbit determination algorithm of space targets with passive observation

Angles-only relative orbit determination for space non-cooperative targets based on passive sensor is subject to weakly observable problem of the relative state between two spacecraft. Previously, the evidence for angles-only observability was found by using cylindrical dynamics, however, the solution of orbit determination is still not provided. This study develops a relative orbit determination algorithm with the cylindrical dynamics based on differential evolution. Firstly, the relative motion dynamics and line-of-sight measurement model for nearcircular orbit are established in cylindrical coordinate system.Secondly, the observability is qualitatively analyzed by using the dynamics and measurement model where the unobservable geometry is found. Then, the angles-only relative orbit determination problem is modeled into an optimal searching frame and an improved differential evolution algorithm is introduced to solve the problem. Finally, the proposed algorithm is verified and tested by a set of numerical simulations in the context of highEarth and low-Earth cases. The results show that initial relative orbit determination(IROD) solution with an appropriate accuracy in a relative short span is achieved, which can be used to initialize the navigation filter.

Interaction mechanism of cyanide with pyrite during the cyanidation of pyrite and the decyanation of pyrite cyanide residues by chemical oxidation

The toxic cyanides in cyanide residues produced from cyanidation process for gold extraction are harmful to the environment.Pyrite is one of the main minerals existing in cyanide residues.In this work,the interaction of cyanide with pyrite and the decyanation of pyrite cyanide residue were analyzed.Results revealed that high pH value,high cyanide concentration,and high pyrite dosage promoted the interaction of cyanide with pyrite.The cyanidation of pyrite was pseudo-second-order with respect to cyanide.The decyanation of pyrite cyanide residue by Na_(2)SO_(3)/air oxidation was performed.The cyanide removal efficiency was 83.9% after 1 h of reaction time under the optimal conditions of pH value of 11.2,SO_(3)^(2-) dosage of 22 mg·g^(-1),and air flow rate of 1.46 L·min^(-1).X-ray photoelectron spectroscopy analysis of the pyrite samples showed the formation of Fe(Ⅲ)and FeSO_(4) during the cyanidation process.The cyanide that adsorbed on the pyrite surface after cyanidation mainly existed in the forms of free cyanide(CN^(-))and ferrocyanide(Fe(CN)_(6)^(4-)),which were effectively removed by Na_(2)SO_(3)/air oxidation.During the decyanation process,air intake promoted pyrite oxidation and weakened cyanide adsorption on the pyrite surface.This study has practical significance for gold enterprises aiming to mitigate the environmental impact related to cyanide residues.

Chemical Composition of Pineapple Press Residues (Ananas comosus) and Effect on Growth Performance of Rabbit (Oryctolagus cuniculus)

With a view to improving rabbit production performance, a trial on the chemical composition of pineapple press residue (Ananas comosus) and the effect of its incorporation in the ration on rabbit growth performance (Oryctolagus cuniculus) was carried out at the KUATE Cunicole Farm in Bandjoun, in Western Cameroon. To do this, 36 rabbits of the local breed, aged 53 days with an average weight of 1337 ± 119 g were distributed and randomly assigned to 3 experimental rations corresponding respectively to treatments or batches T0, T1 and T2. The animals in treatment T0 received a ration containing no pineapple press residue, while those in treatments T1 and T2 received a ration containing 20% and 40% pineapple press residue, respectively. These residues were dried and ground for chemical composition analysis. The feed served as well as refusals from the previous day were weighed each morning to assess feed intake. The animals were weighed every 7 days to assess weight performance. At the end of the trial which lasted 7 weeks, the animals were fasted for 24 hours, then sacrificed to evaluate carcass characteristics and the relative weights of some digestive organs. The results of this study showed that pineapple press residues had a high crude fiber content (19.2%) and energy (2500 Kcal/kg DM). Their incorporation had no significant effect on feed intake and feed conversion ratio. The average live weight, weight gain and average daily weight gain of the animals receiving the ration with 20% inclusion of pineapple press residue were comparable to those of the control group and significantly higher than those of animals fed with 40% inclusion of pineapple residue. The highest carcass yields were obtained with rabbits fed 20% pineapple press residue in their ration. The cost of feed for the production of a kilogram live weight of rabbit tends to decrease with the ration incorporated with 20% pineapple press residue. Pineapple press residues constitute a by-product that can be recycled and their incorporation at 20% can increase rabbit growth performance and reduce production costs.

The Impact of Sleep Determination on Procrastination before Bedtime:The Role of Anxiety

Objective:The importance of good sleep for energy recovery and overall physical and mental health cannot be overstated.However,the increasing competitiveness of society,diversifying lifestyles,and the rapid spread of the internet and electronic devices have significantly impacted people’s sleep patterns,particularly through bedtime procrastination.Therefore,this study aims to investigate the relationship and underlying mechanisms between sleep determination,anxiety,and bedtime procrastination among the Chinese population.Method:The study utilized data from a national survey—the China Residents’Sleep Condition Survey(November 2021,with 6,037 participants).By constructing mediation and moderation models,it analyzed the relationship and mechanisms between sleep determination and bedtime procrastination,highlighting the dual role of anxiety:as a mediator between sleep determination and bedtime procrastination,and as a moderator of their relationship.Results:There was a negative correlation between sleep determination and bedtime procrastination;anxiety was related to an increase in bedtime procrastination behaviors;In the interplay between sleep determination and pre-bedtime procrastination,the regulatory effect of anxiety is found to be more pronounced than its intermediary role,with anxiety significantly diminishing the inverse relationship between sleep determination and procrastination before bedtime.Conclusion:Bedtime procrastination can lead to sleep issues,thus reducing sleep quality.Enhancing sleep determination or alleviating pre-sleep anxiety can help inhibit bedtime procrastination behaviors.Intervening and reducing bedtime procrastination is one of the effective measures to improve sleep quality.

Research Progress on Purification Process, Content Determination and Pharmacological Action of Atractylodin

Atractylodis Rhizoma comes from the dry rhizome of Atractylis lancea or Atractylodes chinensis in the Compositae family,and it is suitable for preventing and treating diseases such as cold,edema,night blindness and rheumatic arthralgia.Atractylodin is the main active component extracted and isolated from Atractylodis Rhizoma.A large number of studies have found that atractylodin has excellent drug activity in improving gastrointestinal emptying,anti-inflammation,inhibiting malignant tumor and reducing blood lipid.In this paper,the purification process and pharmacological activity of Atractylodin were summarized to provide a theoretical basis for basic research,clinical application and further development and utilization of atractylodin.

Determination of Coumoxystrobin Residue in Vegetables by QeEChERS-UPLC-MS/MS

[Objectives]This study was conducted to establish a method for determining residual coumoxystrobin in vegetables using QeEChERS-liquid chromatography-tandem mass spectrometry(QeEChERS-LC-MS/MS).[Methods]The sample was extracted by acetonitrile,and the extract was purified by QeEChERS,concentrated by nitrogen blowing,and then detected.[Results]Coumoxystrobin had a good linear relation in the range of 0.01-10.0 mg/kg,and the linear equation was y=4686.92×x+5683.28,R^(2)=0.999.The limit of detection was 0.001 mg/kg,and the limit of quantitation was 0.003 mg/kg.[Conclusions]The method has the advantages of convenient and fast operation and stable detection process,and can provide technical support for the supervision and monitoring of coumoxystrobin.

Research Progress of QuEChERS Pretreatment Technique in the Detection of Multiple Pesticide Residues

The QuEChERS extraction technique is a pretreatment technique that has been rapidly applied in recent years and is widely used in the field of pesticide residues with many advantages. This technique is based on solid phase extraction (SPE), which uses the interaction between adsorbent and impurities in the matrix to achieve the purpose of purification. The method has easier operation and better purification effect than SPE. In this paper, the research progress of the QuEChERS technique in pesticide residue detection in different fields in recent years and its future development were reviewed, hoping to provide reference for further development and utilization of the QuEChERS technique in pesticide residue detection in the future.

Determination of Chlorogenic Acid,Geniposide,Total Flavonoids and Total Triterpenes in Wulan-13

[Objectives]This study was conducted to establish a method for the determination of chlorogenic acid,geniposide,total flavonoids and total triterpenes in Wulan-13.[Methods]The contents of chlorogenic acid and geniposide were determined by HPLC,and the contents of total flavonoids and total triterpenes were determined by an ultraviolet spectrophotometer.[Results]There was a good linear relation between the mass of chlorogenic acid reference substance and the peak area in the range of 0.05-0.45μg,and the regression equation was Y=2524.1X+3.1943,(r=0.9998).A good linear relationship was found between the mass of gardenoside reference substance and the peak area in the range of 0.776-6.984μg,and the regression equation was Y=1670.5X+64.804,(r=0.9998).There was also a good linear relation between the mass of rutin reference substance and its absorbance in the range of 0.00808-0.04848 mg,and the regression equation was Y=12.916X+0.014,(r=0.999).The mass of oleanolic acid reference substance had a good linear relation with its absorbance in the range of 0.00418-0.0209 mg,and the regression equation was Y=51.89X-0.0839,(r=0.9991).[Conclusions]The content determination method is simple,reliable and reproducible,and suitable for controlling the contents of chlorogenic acid,geniposide,total flavonoids and total triterpenes in Wulan-13.

Research Progress on Detection Techniques of Fungicide Residues in Chinese Chives

Chinese chive is a kind of medicinal and edible plant,with many diseases,and chemical fungicides are usually used for control.In order to find out the risk of pesticide residues in Chinese chives,this paper summarized relevant literatures published in recent years,and sorted out and analyzed the types of pesticides used and detection techniques of common diseases in Chinese chives.

Overexpression of Kdm6b induces testicular differentiation in a temperature-dependent sex determination system

In reptiles,such as the red-eared slider turtle(Trachemys scripta elegans),gonadal sex determination is highly dependent on the environmental temperature during embryonic stages.This complex process,which leads to differentiation into either testes or ovaries,is governed by the finely tuned expression of upstream genes,notably the testis-promoting gene Dmrt1 and the ovary-promoting gene Foxl2.Recent studies have identified epigenetic regulation as a crucial factor in testis development,with the H3K27me3 demethylase KDM6B being essential for Dmrt1 expression in T.s.elegans.However,whether KDM6B alone can induce testicular differentiation remains unclear.In this study,we found that overexpression of Kdm6b in T.s.elegans embryos induced the male development pathway,accompanied by a rapid increase in the gonadal expression of Dmrt1 at 31°C,a temperature typically resulting in female development.Notably,this sex reversal could be entirely rescued by Dmrt1 knockdown.These findings demonstrate that Kdm6b is sufficient for commitment to the male pathway,underscoring its role as a critical epigenetic regulator in the sex determination of the red-eared slider turtle.

Determination of Benzoylaconitine Compounds in the Decoctions of Aconiti Lateralis Radix Praeparata(Heishun Pieces),Trichosanthis Fructus and Their Combination

[Objectives]This study was conducted to determine the contents of benzoylmesaconine,benzoylaconitine and benzoylhypacoitine in the decoctions of Heishun pieces,Trichosanthis Fructus and their combination.[Methods]Heishun pieces,Trichosanthis Fructus and their combination were extracted for different time periods,and then grouped.HPLC was performed using an Agilent ZORBAX SB-C 18 chromatographic column(4.6 mm×250 mm,5μm)and acetonitrile-0.02 mol/L sodium dihydrogen phosphate as the mobile phase at a flow rate of 1 mL/min and a column temperature of 30℃,and the sample volume was 20μL.The detection wavelength was 230 nm.[Results]The total amounts of benzoylmesaconine,benzoylaconitine and benzoylhypacoitine in the single decoction group of Heishun pieces were all significantly different from those in the combined decoction group at corresponding time.[Conclusions]The total content of the benzoylaconitine type increased significantly after the combined decoction of Heishun pieces and Fructus Trichosanthis,which proves the scientificity of"eighteen incompatible medicaments,19 counteraction"in traditional Chinese medicine to some extent.

TLC Identification of Yao Medicine Pileostegia tomentellal and Extraction Technology and Content Determination of Umbelliferone

[Objectives]To establish a TLC and content determination method of Pileostegia tomentellal,with umbelliferone as the indicator component.[Methods]TLC identification was performed by silica gel G thin layer plate with n-hexane-ethyl acetate(4:3)as the developing agent,and the plate was examined by UV lamp(365 nm).The umbelliferone content was determined by HPLC:Inertsil ODS-3 C 18 column(4.60 mm×250 mm,5μm);mobile phase acetonitrile-0.2%phosphoric acid gradient elution;detection wavelength 320 nm,flow rate 1.0 mL/min,column temperature 30℃,injection volume 10μL.[Results]The chromatogram of P.tomentellal showed the same color spot in the same position as that of reference medicinal material,and the spot was clear with good specificity.Umbelliferone showed a good linear relationship when the injection volume was 2.63-131.27μg/mL(R^(2)=0.9997).The average recovery of umbelliferone in the low,middle and high adding groups of P.tomentellal was 99.57%and the RSD was 2.15%.[Conclusions]The method can effectively identify Yao medicine P.tomentellal and accurately determine the content of umbelliferone in medicinal materials,which will provide a scientific basis for the development and utilization of medicinal resources of Yao medicine P.tomentellal.

Retention of harvest residues promotes the accumulation of topsoil organic carbon by increasing particulate organic carbon in a Chinese fir plantation

Background As commonly used harvest residue management practices in subtropical plantations,stem only harvesting(SOH)and whole tree harvesting(WTH)are expected to affect soil organic carbon(SOC)content.However,knowledge on how SOC and its fractions(POC:particulate organic carbon;MAOC:mineral-associated organic carbon)respond to different harvest residue managements is limited.Methods In this study,a randomized block experiment containing SOH and WTH was conducted in a Chinese fir(Cunninghamia lanceolata)plantation.The effect of harvest residue management on SOC and its fractions in topsoil(0–10cm)and subsoil(20–40cm)was determined.Plant inputs(harvest residue retaining mass and fine root biomass)and microbial and mineral properties were also measured.Results The responses of SOC and its fractions to different harvest residue managements varied with soil depth.Specifically,SOH enhanced the content of SOC and POC in topsoil with increases of 15.9%and 29.8%,respectively,compared with WTH.However,SOH had no significant effects on MAOC in topsoil and SOC and its fractions in subsoil.These results indicated that the increase in POC induced by the retention of harvest residue was the primary contributor to SOC accumulation,especially in topsoil.The harvest residue managements affected SOC and its fractions through different pathways in topsoil and subsoil.The plant inputs(the increase in fine root biomass induced by SOH)exerted a principal role in the SOC accumulation in topsoil,whereas mineral and microbial properties played a more important role in regulating SOC dynamics than plants inputs in subsoil.Conclusion The retention of harvest residues can promote SOC accumulation by increasing POC,and is thus suggested as an effective technology to enhance the soil carbon sink for mitigating climate change in plantation management.

Determination of Veterinary Drug Residues in Animal-derived Foods by Liquid Chromatography-Mass Spectrometry

[Objectives]This study was conducted to establish a rapid and effective method for simultaneous extraction of 54 kinds of veterinary drug residues in animal-derived food, including sulfonamides, quinolones, tetracyclines, malachite greens, penicillins, nitroimidazoles, tranquilizers and macrolides, by HPLC-MS. [Methods] The samples were extracted with 80% acetonitrile water(containing 0.1% formic acid), combined with QuEChERS extraction technology and C18 and PSA purification, analyzed by high performance liquid chromatography-mass spectrometry, and quantified by external standard method. The target substances were analyzed on ZORBAX Eclipse C18 chromatographic column using 0.2% formic acid water and 0.2% methanol as mobile phases. The gradient elution mode was used for chromatographic separation and multiple reaction detection. [Results] In the linear range of 0.5-50.0 ng/ml, the linear relationship of the 54 kinds of veterinary drug residues was good, with correlation coefficients(r~2) greater than 0.995, and the detection limits ranged from 0.30 to 1.00 μg/kg. The results showed that the recovery ranged from 75.4% to 118.2% when different matrixes were added for recovery. [Conclusions] This method is simple, efficient, accurate, stable, and highly operable. It is applicable to simultaneous batch screening of veterinary drug residues in animal-derived food, and has high practical application value.

Assessment of Contamination Degree of Oil Residues on a Former Agricultural Site

In this study,our goal is to identify the land surface that has been polluted/degraded by petroleum products or other identified causes through laboratory analysis,to assess the depth of current contamination and to identify the specific causes of contamination.The level of contamination will be assessed by analyzing a total of 90 soil samples,both within the first 30 cm depth and within the 30-60 cm interval.The potential impact of the petroleum activities and their effects on the environment and agricultural development in the area will be evaluated by studying the distribution of the chemical elements analyzed,particularly total petroleum hydrocarbons(TPH).In addition,a thematic map was created using MapSys 10.0 software based on their distribution,indicating the polluted areas using color codes and values.This analysis and mapping revealed that 7,473 square meters of the site were severely contaminated at 30 cm,representing approximately 25% of the site.

Determination of Salvianolic Acid B in Yiqi Huayu Prescription by HPLC

[Objectives]To determine the content of salvianolic acid B in Yiqi Huayu Prescription by HPLC.[Methods]The chromatographic column was ZORBAX Eclipse Plus C 18(4.6 nm×250 nm,5μm);the mobile phase was acetonitrile-0.1%phosphoric acid(21:79),the detection wavelength was 286 nm,the column temperature was 30℃,and the flow rate was 1.0 mL/min.A method for determination of salvianolic acid B in Yiqi Huayu Prescription was established.[Results]The linear relationship of salvianolic acid B was good in the range of 0.0214-0.4064 mg/mL.The regression equation was Y=5995.98984 X-0.07332,r=0.9999.The average recovery rate was 98.88%(RSD=1.6%).[Conclusions]The method is reliable,accurate and specific,and can be used for the determination of salvianolic acid B in Yiqi Huayu Prescription.