断营养影响青梗菜硝酸盐含量的转录组学分析

为降低青梗菜硝酸盐含量,在采收前对其进行断营养处理。生理分析发现,断营养5 d青梗菜产量无明显变化,但根、叶柄和叶片的硝酸盐含量分别降低了49.77%,23.90%,33.39%。转录组比较发现,断营养5 d青梗菜根、叶柄和叶片分别鉴定出301,2270,2271个差异表达基因(DEGs)。基因本体论(GO)分析表明,这些DEGs均主要富集在氮(N)代谢、碳(C)代谢和活性氧(ROS)代谢过程中。在N代谢过程中,根、叶柄和叶片硝酸盐摄取转运蛋白NPF7.2基因下调表达;叶柄和叶片NPF7.2的上游调控因子ERF104下调表达;叶片硝酸盐再转运蛋白NPF2.13和NPF1.1基因上调表达;根和叶片硝酸盐同化关键酶谷氨酰胺合成酶(GS)基因上调表达。在C代谢过程中,叶柄和叶片蔗糖合成关键酶磷酸蔗糖合酶(SPS)基因上调表达。在ROS代谢过程中,根的超氧化物歧化酶(SOD)基因和抗坏血酸过氧化物酶(APX)基因上调表达;叶柄和叶片细胞色素P450、过氧化物酶体和脂肪氧化酶下调表达;叶片过氧化氢酶(CAT)基因和过氧化物酶(POD)基因上调表达。综上,在青梗菜采收前5 d进行断营养处理,不仅可以保证产量不受影响,还可以降低硝酸盐含量,提高品质。

采收前补光对营养液断钾下生菜生长及品质的影响

以意大利耐抽薹生菜为试材,在塑料大棚水培条件下,研究了营养液处理(1/2园试配方营养液,采前两周施用不含钾的1/2园试配方营养液)和采前补光时长处理(0 h、24 h、48 h、1week)组合对生菜生物量、品质、矿物质元素含量的影响。结果表明:营养液断钾处理降低了生菜叶片中的钾含量,提高了钠、钙、镁含量。随着补光时间的延长,生菜中钾、钠、钙、镁含量呈下降趋势,T48处理的矿物质元素含量最少。采前补光处理不同程度地提高了生菜中的可溶性糖、可溶性蛋白、VC、游离氨基酸含量,同时提高生菜的抗氧化能力,同时降低了硝酸盐含量。营养液采前两周断钾配合采前48 h连续LED蓝光补光处理为低钾优质生菜生产的适宜方案。

应急与兜底:重大突发公共危机下的美国学生营养餐项目研究

美国是全球范围内为数不多的在重大突发公共危机下依然能为停课在家的学生供应营养餐的国家之一。在新冠疫情防控整体失利、全社会需食物救济的人口剧增的大背景下,美国借助既有机制和创新手段基本保障了3000万贫困家庭学生营养不中断。一方面,突发情况下自动激活的应急机制为资源调配、管理协调提供了基本的制度保障;适用于假期和突发情况下的专项营养餐项目在确保学生直接获得食物补助方面扮演了主要角色;2009年甲型H1N1流感期间形成的有效应对重大突发公共危机、确保学生营养不中断的做法在新冠疫情期间发挥了一定的作用;另一方面,新冠疫情爆发伊始就被充分激活的应急机制有助于停课不停营养;信息化手段辅助学生资格认证,助力精准发放营养膳食补助;出钱又出力的民间组织与官方机构配合默契,一定程度上填补了官方营养餐项目力度不足的方面。美国的经验为完善和健全突发公共危机下我国学生营养餐项目的应急管理体系提供了参考。我国应拓宽学生营养餐的保障路径,逐步建立以村(社区)为依托的学生营养餐应急和假期供应体系;充分利用大数据的优势,尽早建立精准的学生营养餐资格认证体系;鼓励民间力量参与到学生营养餐事业中来,形成国家和民间力量互补的学生营养餐供给体系,最终实现重大突发公共危机下学生营养不中断的目标。

Long-term modulation of the immune system by perinatal nutrition

Nutrition during perinatal period is more critical for the developme nt of the immune system than during adulthood, and the relationship between earl y nutrition and diseases in later life has been established. In humans and labor atory animals, the plasticity of metabolic function in foetuses or neonates enab les them to adapt to malnutrition for survival; however, such an adaptation, as usually evidenced by retarded growth, stunted development of lymphoid organs and impaired immunocompetence, can maintain and persist into later life even when n utrition is improved. Early nutrition may thus programme' the immune system of a nimals. Limited experimental studies have also revealed that long-term immunity against nematode parasites in sheep can be enhanced by a short-term protein su pplementation shortly after weaning, a form of 'nutritional programming', but su ch an effect appears to vanish if the nutritional status of young animals alread y meets at least the requirement for maintenance.

Effect of resuscitation after selective cerebral ultraprofound hypothermia on expressions of nerve growth factor and glial cell line-derived neurotrophic factor in the brain of monkey

Objective To investigate the expression of nerve growth factor （NGF） and glial cell line-derived neurotrophic factor （GDNF） in monkeys of resuscitation after selective cerebral ultraprofound hypothermia and blood flow occlusion. Methods The monkeys were immediately removed brain after death in operation of group A （identical temperature perfusion group） and group B （ultraprofound hypothermia perfusion group）. Immunohistochemical technique was used to determine frontal cellular expression of NGF and GDNF. Statistics were analyzed by ANOVA analyses with significance level at P 〈 0.05. Results The expressions of NGF and GDNF in the group B were significantly higher than those in the group A （P 〈 0.05）. Conclusion NGF and GDNF increased significantly in the monkeys of resuscitation after selective cerebral ultraprofound hypothermia and blood flow occlusion. It may be a protective mechanism for neuron survival and neural function recovery.

A NEW APPROACH TO GENE DIAGNOSIS OF DUCHENNE/BECKER MUSCULAR DYSTROPHY──AMPLIFIED FRAGMENT LENGTH POLYMORPHISM

Four (CA)n repeats, located in introns 44, 45, 49 and 50 of the dystrophin gene., were evaluated in Chinese. These loci are highly polymorphic, with polymorphism information contents of 0. 872, 0. 772, 0. 870 and 0. 718, respectively. All four loci can be easily amplified and labelled using two duplex PCR reactions with α-32P-dCTP and can be detected by denaturing polyacrylamide gel electrophoresis. Using these four loci and the two polymorphic (CA)n repeats located at the 5' and 3' ends of the dystrophin gene, we have developed a new PCR-based procedure -Amp-FLP (amplified fragment length polymorphism) linkage analysis for the gene diagnosis of DMD/BMD. This method can detect intragenic recombination rapidly and efficiently and greatly. improves the success rate of carrier detection and prenatal diagnosis in non-deletion DMD/BMD families. All of the loci used in this procedure are intragenic. In addition, the loci in introns 44. 45, 49 and 50 are located in the deletion-prone region of the dystrophin gene, making them valuable and useful in the identification of deletion mutations. Here we report one case of deletion detection using these four loci.

Advances in the diagnosis and treatment of patients with cancer cachexia

Cachexia is a common complication with an incidence rate of 50%–80% in cancer patients. It is also responsible for 20% of mortality among these patients. Cachexia can significantly reduce the efficacy of antitumor therapies and increase treatment-related toxicity and adverse effects in cancer patients. This increases the symptom burden in patients, affects their quality of life, and ultimately shortens their survival time. The mechanism underlying the development of cachexia is complex and diverse and involves various factors and pathways, each playing an important role. Treatment approaches for cachexia are multimodal, including nutrition support therapy, appetite stimulants, and therapeutic drugs that specifically target the mechanism behind the disease. In recent years, we have gradually gained a better understanding of cachexia, and significant progress has been made in delineating molecular mechanisms, staging and diagnosis, and therapeutic drug treatment of cancer cachexia. This article reviews the research progress of cancer cachexia based on these contexts.

Treatment of upper gastrointestinal fistula and leakage with personal stage nutrition support

AIM： To investigate the feasibility of treatment for upper gastrointestinal fistula and leakage with personal stage nutrition support. METHODS： Forty-three patients with upper gastrointestinal fistula and leakage were randomly divided into two groups. Patients in group A were treated with personal stage nutrition support and patients in group B were treated with total parental nutrition （TPN） in combination with operation. Nutritional states of the candidates were evaluated by detecting albumin （AIb） and pre-AIb. The balance between nutrition and hepatic function was evaluated by measurement of aspartate aminotransferase （AST）, alanine aminotransferase （ALT） and total bilirubin （Tbill） before and after operation. At the same time their complications and hospitalized time were surveyed. RESULTS： Personal stage nutrition support improved upper gastrointestinal fistula and leakage. The nutrition state and hepatic function were better in patients who received personal stage nutrition support than in those who did not receive TPN. There was no significant difference in the complication and hospitalized time in the two groups of patients. CONCLUSION： Upper gastrointestinal fistula and leakage can be treated with personal stage nutrition support which is more beneficial for the post-operation recovery and more economic than surgical operation.

Preventive strategies for feeding intolerance among patients with severe traumatic brain injury:A cross-sectional survey

This study aimed to investigate the application status of preventive measures for feeding intolerance in patients with severe traumatic brain injury(STBI)in China and analysis the differences and their causes.Methods A cross-sectional survey was conducted.From December 2019 to January 2020,ICU nurses and physicians of 89 hospitals in China were surveyed by using a questionnaire on preventive strategies for feeding intolerance in patients with STBI.The questionnaire included two parts:the general information of participants(10 items)and application of preventive measures for feeding intolerance in STBI patients(18 items).Results Totally 996 nurses and physicians completed the questionnaire.Among various methods,gastrointestinal symptoms(85.0%)and injury severity(71.4%)were mostly used to assess gastrointestinal functions and risk of feeding intolerance among STBI patients,respectively.Initiating enteral nutrition(EN)within 24–48 h(61.5%),nasogastric tubes(91.2%),30°–45°of head-of-bed elevation(89.5%),continuous feeding by pump(72.9%),EN solution temperature of 38–40°C(65.5%),<500 ml initial volume of EN solution(50.0%),monitoring gastric residual volume with a syringe(93.7%),and assessing gastric residual volume every 4 h(51.5%)were mostly applied for EN delivery among STBI patients.Prokinetic agents(73.3%),enema(73.6%),probiotics(79.0%),antacid agents(84.1%),and non-nutritional preparations as initial EN formula(65.6%)were commonly used for preventing feeding intolerance among STBI patients.Conclusions The survey showed that nurses and clinicians in China have a positive attitude towards preventive strategies for feeding intolerance.However,some effective new technologies and methods have not been timely applied in clinical practice.We suggest that managers,researchers,clinicians,nurses,and other health professionals should collaborate to explore effective and standard preventive strategies for feeding intolerance among patients with STBI.

Avocado Nutritional Diagnosis （Persea americana Mill.） ＂Hass＂, Soil Fertility and Water Quality in Ocuituco, Morelos

Morelos is the fourth in area cultivated and production volume of avocado. Of the 13 municipalities where it is farmed, Ocuituco represents 43.51% and Tetela del Volain 27.53%. Despite being one of the main fruit species in Morelos, no information related to the fertility of the soil where it is grown, the quality of water available for irrigation and nutritional status of this important fruit for the state. The study was conducted in the municipality of Ocuituco which identified three agro-habitats taking into account climate, landform, soil type and altitude. In each agro-habitat were carried out soil sampling to determine the physical and chemical characteristics based on the Mexican Official Standard NOM-021-SEMARNAT-2000, the chemical quality of water for irrigation as described by Richards （1954） and crop nutrient status of avocado ＂Hass＂ according to the methodology described by Maldonado （2002）. The soils had different physical and chemical characteristics, as well as the nutritional status of avocado trees in the three agro-habitats. The trees had excessive concentration of CI, Cu and Zn. Indices of optimal percentage deviation expressed different nutritional requirements. The water used for irrigation was of low salinity and sodium content, so it can be used without restrictions.

Multiplex ligation-dependent probe amplification for rapid detection of deletions and duplications in the dystrophin gene

Objective：Duchenne muscular dystrophy （DMD） and Becker muscular dystrophy （BMD） are X-linked disorders caused by mutations in the dystrophin gene. The majority of recognized mutations are copy number changes of individual exons. The objective of the present study was to assess the multiplex ligation-dependent probe amplification （MLPA） effects of detection of gene mutations. Methods： Samples of 20 control males and 80 males and their mothers referred to our diagnostic facility on the clinical suspi- cion of DMD or BMD were tested by MLPA and multiplex PCR. Results ： The mean DQs for all peak of 20 control male samples was 1.02 （range from 0.83 to 1.21） by MLPA. Deletions or duplications were iden- tified in 6 out of 31 families that had been previously tested as negative by multiplex PCR. One case of complex rearrangement involving a duplication of two regions： dupEX3-9 and dupEX 17-41 were found by MLPA. Conclusions： MLPA is a highly sensitive method and rapid alternative to multiplex PCR for detec- tion of DMD and BMD.

Structural analysis of DMD gene and its clinical application in Chinese.Ⅰ. Bgl Ⅱ exon-containing fragment,RFLP and carrier detection

This article is one of the serial studies oll the characteristics of the molecular structure for dystrophin gene in Chinese. By using the entire dystrophin cDNA (14 kb) as a probe- the number and RFLPs of Bgl Ⅱ exon-containing fragments of the dystrophin gene were analysed. Four new Bgl Ⅱ fragments were found, two of them (3.7 and 6.2 kb) detected by comparing the hybridization patterns with cDNA1-2a. 1a and 2a, one (9.3 kb) from the hybridization pattern with cDNA 9 by lengthening migrating distance of DNA fragments in electrophoresis. and another one (4.0 kb) by comparing the patterns with cDNA 11-14,11a- 11b’ 11c-12a and 14. The results indicated that the number of Bgl Ⅱ exon-containing fragments should be 59 rather than 55 reported previously, which laid the foundation of the Bgl Ⅱ partial restriction map for dystrophin gene. Three of the four RFLPs found in Caucacian appear in the hybridization patterns of three subclones, i.e.cDNA 2b-3. cDNA 4-5, and cDNA 5b-7.’ The values of expected heterozygote frequency (EHF) were 0.33, 0.33and 0.40 and the observed heterozygote frequency (OHF)were 0.40. 0.40 and 0.48 respectively. Meanwhile, two new rare allelic fragments (15 kb) were found in RFLPs from Bgl Ⅱ/2b-3 and Bgl Ⅱ/4-5a patterns respectively. These Bgl Ⅱ RFLPs and four XbaI RFLPs documented in our laboratory, have been used to detect the carrier in 7 DMDfamilies and 1 BMD family. Of the 69 individuals from the 8 families- 11 females were diagnosed as the carriers with DMD mutation, 4 females as the doubtful carriers, 12 females were defined as normal genotype and 2 females as probably normal. The results suggest that the carrier testing method based on dosage intensity analysis and genotype analysis by using dystrophin cDNA as a probe will be more sensitive and accurate.

Validation of a Critical Nitrogen Curve for Summer Maize in the North China Plain

The concept of critical N concentration(N_c)has been widely used in agronomy as the basis for diagnosis of crop N status,and allows discrimination between field situations of sub-optimal and supra-optimal N supply.A critical N dilution curve of N_c=34.0W^(-0.37),where W is the aboveground biomass(Mg DM ha^(-1))and N_c the critical N concentration in aboveground dry matter(g kg^(-1)DM),was developed for spring maize in Europe.Our objectives were to validate whether this European critical N dilution curve was appropriate for summer maize production in the North China Plain(NCP)and to develop a critical N dilution curve especially for summer maize production in this region.In total 231 data points from 16 experiments were used to test the European critical N dilution curve.These observations showed that the European critical N dilution curve was unsuitable for summer maize in the NCP,especially at the early growth stage.From the data obtained,a critical N dilution curve for summer maize in the NCP was described by the equation of N_c=27.2W^(-0,27),when aboveground biomass was between 0.64 and 11.17 Mg DM ha^(-1).Based on this curve,more than 90%of the data for the N deficiency supply treatments had an N nutrition index(NNI)<1 and 92%of the data for the N excess supply treatments had an NNI>1.

Multifractal methods for rapeseed nitrogen nutrition qualitative diagnosis modeling

Nutrition diagnosis plays a key role in the crop＇s growth, which has mainly been car- ried out in the field by agricultural workers. Currently, automatic nutrition recognition technologies have been widely used in this field. A procedure is proposed in this paper to diagnose nitrogen nutrition non-destructively for rapeseed qualitatively based on the multifractal theory. Twelve texture parameters are given by the method of multifractal detrended fluctuation （MF-DFA）, which contains six generalized Hurst exponents and six relative multifractal parameters that are used as features of the rapeseed leaf images for identifying the two nitrogen levels, namely, the N-mezzo and the N-wane. For the base leaves, central leaves and top leaves of the rapeseed plant and the three-section mixed samples, three parameters combinations are selected to conduct the work. Five classifiers of Fisher＇s linear discriminant algorithm （LDA）, extreme learning machine （ELM）, support vector machine and kernel method （SVMKM）, random decision forests （RF） and K-nearest neighbor algorithm （KNN） are employed to calculate the diagno- sis accuracy. An interesting finding is that the best diagnose accuracy is from the base leaves of the rapeseed plant. It is explained that the base leaf is the most sensitive to the nitrogen deficiency. The diagnose effect by the base leaves samples is outshining the existing result significantly for the same leaves samples. For the mixed samples, the aver- aged discriminant accuracy reaches 97.12% and 97.56% by SVMKM and RF methods with the 10-fold cross-validation respectively. The resulting high accuracy on N-levels identification shows the feasibility and efficiency of our method.