Multiple enzymatic activities of a Sir2-HerA system cooperate for anti-phage defense.

In response to the persistent exposure to phage infection, bacteria have evolved diverse antiviral defense mechanisms. In this study, we report a bacterial two-component defense system consisting of a Sir2 NADase and a HerA helicase. Cryo-electron microscopy reveals that Sir2 and HerA assemble into a ∼1 MDa supramolecular octadecamer. Unexpectedly, this complex exhibits various enzymatic activities, including ATPase, NADase, helicase, and nuclease, which work together in a sophisticated manner to fulfill the antiphage function. Therefore, we name this defense system "Nezha" after a divine warrior in Chinese mythology who employs multiple weapons to defeat enemies. Our findings demonstrate that Nezha could sense phage infections, self-activate to arrest cell growth, eliminate phage genomes, and subsequently deactivate to allow for cell recovery. Collectively, Nezha represents a paradigm of sophisticated and multifaceted strategies bacteria use to defend against viral infections.

Uncovering novel drug targets for bipolar disorder: a Mendelian randomization analysis of brain, cerebrospinal fluid, and plasma proteomes.

BACKGROUND: There is a clear demand for innovative therapeutics for bipolar disorder (BD). METHODS: We integrated the largest BD genome-wide association study (GWAS) dataset (NCase = 41 917, NControl = 371 549) with protein quantitative trait loci from brain, cerebrospinal fluid, and plasma. Using a range of integrative analyses, including Mendelian randomization (MR), Steiger filter analysis, Bayesian colocalization, and phenome-wide MR analysis, we prioritized novel drug targets for BD. Additionally, we incorporated data from the UK Biobank (NCase = 1064, NControl = 365 476) and the FinnGen study (NCase = 7006, NControl = 329 192) for robust biological validation. RESULTS: Through MR analysis, we found that in the brain, downregulation of DNM3, MCTP1, ABCB8 and elevation of DFNA5 and PDF were risk factors for BD. In cerebrospinal fluid, increased BD risk was associated with increased levels of FRZB, AGRP, and IL36A and decreased CTSF and LRP8. Plasma analysis revealed that decreased LMAN2L, CX3CL1, PI3, NCAM1, and TIMP4 correlated with increased BD risk, but ITIH1 did not. All these proteins passed Steiger filtering, and Bayesian colocalization confirmed that 12 proteins were colocalized with BD. Phenome-wide MR analysis revealed no significant side effects for potential drug targets, except for LRP8. External validation further underscored the concordance between the primary and validation cohorts, confirming MCTP1, DNM3, PDF, CTSF, AGRP, FRZB, LMAN2L, NCAM1, and TIMP4 are intriguing targets for BD. CONCLUSIONS: Our study identified druggable proteins for BD, including MCTP1, DNM3, and PDF in the brain; CTSF, AGRP, and FRZB in cerebrospinal fluid; and LMAN2L, NCAM1, and TIMP4 in plasma, delineating promising avenues to development of novel therapies.

The bacterial pathogen Pseudomonas plecoglossicida, its epidemiology, virulence factors, vaccine development, and host-pathogen interactions.

OBJECTIVE: Pseudomoans plecoglossicida has been identified as a fish pathogen since 2000 and has caused serious infections in cultured Large Yellow Croakers Larimiththys crocea in coastal eastern China during recent years. METHODS: Published literatures of this pathogen have been reviewed. RESULT: Several strains with high genomic similarity have been isolated and identified; the bacteria induce natural infection at lower water temperatures (12.0-25.5°C) and induce numerous granulomas and nodules in the visceral organs of croakers. Researchers have investigated the epidemiology of P. plecoglossicida infection, identified major virulence factors, searched for pathogenic genes, analyzed host-pathogen interactions, and endeavored to develop efficient vaccines. CONCLUSION: This paper provides an overview of these research advances to elucidate the virulence mechanisms of the pathogen and to promote vaccine development against infection.

Small cell lung cancer transformation: From pathogenesis to treatment.

Small cell lung cancer (SCLC) is a type of neuroendocrine tumor with high malignancy and poor prognosis. Besides the de novo SCLC, there is transformed SCLC, which has similar characteristics of pathological morphology, molecular characteristics, clinical manifestations and drug sensitivity. However, de novo SCLC and transformed SCLC have different pathogenesis and tumor microenvironment. SCLC transformation is one of the mechanisms of resistance to chemotherapy, immunotherapy, and targeted therapy in NSCLC. Two hypotheses have been used to explain the pathogenesis of SCLC transformation. Although SCLC transformation is not common in clinical practice, it has been repeatedly identified in many small patient series and case reports. It usually occurs in epidermal growth factor receptor (EGFR) mutant lung adenocarcinoma after treatment with tyrosine kinase inhibitors (TKIs). SCLC transformation can also occur in anaplastic lymphoma kinase (ALK)-positive lung cancer after treatment with ALK inhibitors and in wild-type EGFR or ALK NSCLC treated with immunotherapy. Chemotherapy was previously used to treat transformed SCLC, yet it is associated with an unsatisfactory prognosis. We comprehensively review the advancements in transformed SCLC, including clinical and pathological characteristics, and the potential effective treatment after SCLC transformation, aiming to give a better understanding of transformed SCLC and provide support for clinical uses.

GhBZR3 suppresses cotton fiber elongation by inhibiting very-long-chain fatty acid biosynthesis.

The BRASSINAZOLE-RESISTANT (BZR) transcription factor is a core component of brassinosteroid (BR) signaling and is involved in the development of many plant species. BR is essential for the initiation and elongation of cotton fibers. However, the mechanism of BR-regulating fiber development and the function of BZR is poorly understood in Gossypium hirsutum L. (cotton). Here, we identified a BZR family transcription factor protein referred to as GhBZR3 in cotton. Overexpression of GhBZR3 in Arabidopsis caused shorter root hair length, hypocotyl length, and hypocotyl cell length, indicating that GhBZR3 negatively regulates cell elongation. Pathway enrichment analysis from VIGS-GhBZR3 cotton plants found that fatty acid metabolism and degradation might be the regulatory pathway that is primarily controlled by GhBZR3. Silencing GhBZR3 expression in cotton resulted in taller plant height as well as longer fibers. The very-long-chain fatty acid (VLCFA) content was also significantly increased in silenced GhBZR3 plants compared with the wild type. The GhKCS13 promoter, a key gene for VLCFA biosynthesis, contains two GhBZR3 binding sites. The results of yeast one-hybrid, electrophoretic mobility shift, and luciferase assays revealed that GhBZR3 directly interacted with the GhKCS13 promoter to suppress gene expression. Taken together, these results indicate that GhBZR3 negatively regulates cotton fiber development by reducing VLCFA biosynthesis. This study not only deepens our understanding of GhBZR3 function in cotton fiber development, but also highlights the potential of improving cotton fiber length and plant growth using GhBZR3 and its related genes in future cotton breeding programs.

Stable and durable antibody responses in SARS-recovered donors vaccinated with inactivated SARS-CoV-2 vaccine.

Whether the immune imprinting caused by severe acute respiratory syndrome coronavirus (SARS-CoV) affects the efficiency of SARS-CoV-2 vaccination has attracted global concern. Little is known about the dynamic changes of antibody response in SARS convalescents inoculated with three doses of inactivated SARS-CoV-2 vaccine although lack of cross-neutralizing antibody response to SARS-CoV-2 in SARS survivors has been reported. We longitudinally examined the neutralizing antibodies (nAbs) against SARS-CoV and SARS-CoV-2 as well as spikes binding IgA, IgG, IgM, IgG1, and IgG3 antibodies in 9 SARS-recovered donors and 21 SARS-naïve donors. Stably higher nAbs and spike antigens-specific IgA, IgG antibodies against SARS-CoV-2 were observed in SARS-recovered donors compared with SARS-naïve donors during the period with two doses of BBIBP-CorV vaccination. However, the third-dose BBIBP-CorV stimulated a sharply and shortly higher increase of nAbs in SARS-naïve donors than in SARS-recovered donors. It is worth noting that, regardless of prior SARS infection, the Omicron subvariants were found to subvert immune responses. Moreover, certain subvariants such as BA.2, BA.2.75, or BA.5 exhibited a high degree of immune evasion in SARS survivors. Interestingly, BBIBP-CorV recalled higher nAbs against SARS-CoV compared with SARS-CoV-2 in SARS-recovered donors. In SARS survivors, a single dose of inactivated SARS-CoV-2 vaccine provoked immune imprinting for the SARS antigen, providing protection against wild-type SARS-CoV-2, and the earlier variants of concern (VOCs) including Alpha, Beta, Gamma, and Delta but not against Omicron subvariants. As such, it is important to evaluate the type and dosage of SARS-CoV-2 vaccine for SARS survivors.

Nitroarenes and nitroalkenes as potential amino sources for the synthesis of N-heterocycles.

Nitro-compounds are one of the cheapest and most readily available materials in the chemical industry and are commonly utilized as versatile building blocks. Previously, the synthesis of N-heterocycles was largely based on anilines. The utilization of nitroarenes and nitroalkenes for the synthesis of N-heterocyclic compounds can save at least one step, however, as compared to anilines. Thus, considerable attention has been paid to nitroarenes and nitroalkenes as new potential amino sources. Significant progress has been made in the reductive cyclization of nitroarenes or nitroalkenes to access various N-heterocycles in recent years. Herein, we comprehensively summarize the recent progress in the construction of N-heterocycles using nitroarenes and nitroalkenes as potential amino sources. The compatibility of the reaction substrate, its mechanism, applications, advantages, and limitations in this field are also discussed in detail.

Discovery of novel hypoxia-activated, nitroimidazole constructed multi-target kinase inhibitors on the basis of AZD9291 for the treatment of human lung cancer.

A group of 4-(1-methyl-1H-indol-3-yl)pyrimidin-2-amine derivatives containing a hypoxia-activated nitroimidazole group were designed as EGFR inhibitors. Among this series, A14 was identified as the optimal compound, exhibiting potent anti-proliferative activities against H1975 and HCC827 cells. Under hypoxic condition, the anti-proliferative activities of A14 improved by 4-6-fold (IC50 < 10 nM), indicating its hypoxia-selectivity. A14's high potency may be attributed to its inhibition against multiple kinases, including EGFR, JAK2, ROS1, FLT3, FLT4 and PDGFRα, which was confirmed by binding assays on a panel of 30 kinases. Furthermore, A14 exhibited good bio-reductive property and could bind with nucleophilic amino acids after being activated under hypoxic conditions. With its anti-proliferative activities and selectivity for hypoxia and oncogenic kinases, A14 shows promise as a multi-target kinase inhibitor for cancer therapy.

CRISPR/Cas13d targeting GZMA in PARs pathway regulates the function of osteoclasts in chronic apical periodontitis.

Chronic apical periodontitis is a prevalent oral disease characterized by bone loss, and its underlying mechanisms remain unclear. This study aimed to investigate the role and mechanism of the serine protease GZMA in osteoclasts during chronic apical periodontitis. To address this, we employed crRNA/Cas13d to inhibit GZMA expression and examined its impact on osteoclast behavior. Our findings revealed that GZMA plays a significant role in promoting osteoclast cell proliferation while inhibiting cell apoptosis. Additionally, the inhibition of GZMA led to a notable increase in miR-25-3p expression, which, in turn, downregulated the expression of TGF-ß. Consequently, the reduction in TGF-ß expression led to a decrease in PAR1 expression within the PARs pathway. These results suggest that GZMA might serve as a promising therapeutic target for the treatment of chronic apical periodontitis. Furthermore, our study highlights the potential of targeting GZMA using crRNA/Cas13d as a valuable approach for future therapeutic interventions.

Effect and mechanism of fluctuant glucose on restraining implant osseointegration in diabetes.

OBJECTIVES: The objectives of the study was to discuss the effect and mechanism of fluctuant glucose (FG) on implant osseointegration in type 2 diabetic mellitus (T2DM). MATERIALS AND METHODS: Rats were divided into control, T2DM and FG group, and the implants were inserted into their femurs. Micro-CT and histological analysis were used to evaluate the effect on osseointegration in vivo. And we investigated the effect of different conditions (normal, control, high glucose, and FG medium) on rat osteoblast in vitro. Then transmission electron microscope (TEM) and Western blot were used to evaluate the endoplasmic reticulum stress (ERS) response. Finally, 4-PBA, an inhibitor of ERS, was added into different conditions to observe the functions of osteoblast. RESULTS: In vivo, Micro-CT and histological analysis showed that the percentage of osseointegration in FG rats were lower than other two group. In vitro, the results demonstrated that the adhesion of the cells becomes worst, and osteogenic ability was also severely impaired in FG group. In addition, FG could induce more serious ERS and 4-PBA could improve the dysfunction of osteoblasts induced by FG. CONCLUSION: Fluctuant glucose could restrain the implant osseointegration in T2DM, and the effect was more obvious than consistent high glucose by a possible mechanism of activation ERS pathway.

Experience of patients with diabetic retinopathy: A qualitative study.

AIMS: To understand the status quo and needs of self-management of patients with diabetic retinopathy (DR) and to provide a reference for formulating management programs that meet the needs of these patients. DESIGN: A qualitative interview study. METHODS: Semi-structured, in-depth interviews were conducted between November and December 2021. A purposive sample of 15 patients with DR who were hospitalized in the Retinal Department of Eye Hospital was recruited. Colaizzi's analysis was used to organize and analyse the interview data. This study followed the Consolidated Criteria for Reporting Qualitative Research (COREQ) checklist. RESULTS: The experience of patients with DR can be summarized into four themes: (1) lack of DR knowledge, (2) low quality of life, (3) poor self-management behaviour and (4) seek for support from many aspects. CONCLUSION: Patients with DR lack disease knowledge and have poor self-management abilities and adherence. Medical staff should provide personalized care according to the patient's self-management status and needs, promote the establishment of self-management behaviours and prevent and delay disease progression. IMPACT: This study helps assist medical staff in the early management of patients with DR and provides a reference for the construction of prevention programs for patients.

Comparative analysis of anchorage strength and histomorphometric changes after implantation of miniscrews in adults and adolescents: an experimental study in Beagles.

OBJECTIVES: This study aimed to explore the differences in anchorage strength and histomorphometric changes in orthodontic miniscrews between adult and adolescent beagles. MATERIAL AND METHOD: Six adult beagles and six young beagles were used as experimental subjects, and eight miniscrews were symmetrically placed in the posterior mandible of each dog. Measurement of the displacement (mm) of two adjacent miniscrews after load application was performed to compare the anchorage strength between the adult and adolescent groups. Three intravital bone fluorochromes (oxytetracycline, calcein green, xylenol orange) were administered postoperatively to mark the active bone-forming surface. Subsequently, the mineral apposition rate and bone-implant contact ratio were measured for dynamic and static histomorphometry. Finally, the expression levels of the RANKL/OPG ratio were evaluated by immunohistochemistry. RESULTS: The average displacement of miniscrews in the adult group was significantly less than that in the adolescent group after load application. For histomorphometry analysis, the mineral exposure rate in the adolescent group was higher than that in the adult group with or without force application. In addition, more fractures and new bone formation but deceased bone-implant contact ratios were observed in the adolescent group than in the adult group. The ratio of RANKL/OPG expression increased more in the adolescent group than in the adult group. CONCLUSION: Miniscrews do not remain in the same position as skeletal anchors, and the amount of displacement was higher in adolescent group than that in adult group, reflecting the weaker anchorage strength of miniscrews in adolescents due to the higher bone turnover rate and active bone remodelling. Therefore, it is feasible to apply orthodontic loading to the miniscrews in adult patients earlier, even immediately, but it is recommended to wait a period for the adolescents.

Characterization of 4 deletion mutants of Pseudomonas plecoglossicida and their potential for live attenuated vaccines in large yellow croaker (Larimichthys crocea).

To search for live attenuated vaccines (LAV) candidates against Pseudomonas plecoglossicida, the causative agent of the visceral granulomas disease in farmed large yellow croaker (Larimichthys crocea), two type Ⅵ secretion systems (T6SS) and a predicted α/ß fold family hydrolase encoding gene, ORF4885 were targeted to construct deletion mutants. The biological profiles of 4 mutants were characterized; LD50 to the croakers detected, in vivo survival post-infection investigated， relative percent of survival (RPS) of the croakers 28d post-vaccination determined, and transcription of five immunity-related genes of the treated fish was quantified. On comparison to the WT, the mutants revealed similar growth curves in 11h; swarming motility of Δ4885 declined significantly at 72h post-incubation (P < 0.05); ΔS1Δ4885 showed significantly poor biofilm formation and weak resistance to fish serum bactericidal activity (P < 0.05). LD50 of the mutants were much higher than the WT, indication of strong virulence attenuation; in vivo survival test showed the mutant ΔS1Δ4885 and ΔS1ΔS3 were eliminated by the host 10d post-infection, demonstration of the safety and potentiality to be LAV candidates. Immunization with the mutant ΔS1Δ4885 provided higher RPS than ΔS1ΔS3. Transcription of IgT was significant in all immunized groups while IgM increased only in intraperitoneally injected groups. This study successfully searched a quite safe and strong immunogenic LAV candidate to defeat P. plecoglossicida infection.

Design, synthesis and biological evaluation of novel tumor hypoxia-activated EGFR tyrosine kinase inhibitors.

Hypoxia is widespread in solid tumors, such as NSCLC, and has become a very attractive target. On the basis of AZD9291 scaffold, novel hypoxia-targeted EGFR inhibitors without the acrylamide warhead but containing hypoxic reductive activation groups were described. Among them, compound JT21 exhibited impressive inhibitory activity (IC50 = 23 nM) against EGFRL858R/T790M and displayed about 21-fold inhibitory activity decrease against EGFRwt. Under hypoxia, JT21 exhibited more significant proliferation inhibitory activities against H1975 cells (IC50 = 7.39 ± 2.20 nM) and HCC827 cells (IC50 = 5.88 ± 0.85 nM) than that of AZD9291, which was about 5 times more effective than normoxia activities. Meanwhile, the weak inhibition effects on A549 and BEAS-2B cells suggested JT21 might be a selective inhibitor for EGFR mutations with low toxicity. Furthermore, JT21 could induce apoptosis of H1975 cells under hypoxia and showed good bio-reductive property.

Agaricus bisporus-Derived Glucosamine Hydrochloride Facilitates Skeletal Injury Repair through Bmp Signaling in Zebrafish Osteoporosis Model.

Glucosamine hydrochloride (GAH), one of the most basic and important derivatives of chitin, is obtained by hydrolysis of chitin in concentrated hydrochloric acid. At present, little is known about how GAH functions in skeletal development. In this report, we demonstrate that GAH, extracted from the cell wall of Agaricus bisporus, acts in a dose-dependent manner to promote not only cartilage and bone development in larvae but also caudal fin regeneration in adult fish. Furthermore, GAH treatment causes a significant increase in expression of bone-related marker genes, indicating its important role in promoting skeletal development. We show that in both larval and adult osteoporosis models induced by high iron osteogenic defects are significantly ameliorated after treatment with GAH, which regulates expression of a series of bone-related genes. Finally, we demonstrate that GAH promotes skeletal development and injury repair through bone morphogenetic protein (Bmp) signaling, and it works at the downstream of the receptor level. Taken together, our findings not only provide a strong research foundation and strategy for the screening of natural osteoporosis drugs and product development using a zebrafish model but also establish the potential for the development of Agaricus bisporus-derived GAH as a new drug for osteoporosis treatment.

van der Waals force layered multiferroic hybrid perovskite (CH3NH3)2CuCl4 single crystals.

In inorganic-organic perovskites, the three-dimensional arrangement of the organic group results in more subtle balance of charge, spin and space, thereby providing an attractive route toward new multiferroics. Here we report the existing of multiple ferroic orderings in inorganic-organic layered perovskites with relative strong hydrogen bond ordering of the organic chains intra plane. In addition, the inter plane in perovskite is stacking via van der Waals force. However, such magnetoelectric coupling properties for this compound have not been reported since it is difficult to characterize the properties in single crystals since most of the hybrid perovskites are usually deliquescent and unstable when exposed to air. To deal with these problems, we synthesized a (CH3NH3)2CuCl4 single crystal by using a simple evaporation technique, and demonstrated ferroelectric, magnetic and magneto-electric properties of (CH3NH3)2CuCl4. The internal hydrogen bonding of easily tunable organic unit combined with 3d transition-metal layers in such hybrid perovskites make (CH3NH3)2CuCl4 a multiferroic crystal with magnetoelectrical coupling and offer an new way to engineer multifunctional multiferroic.

Establishment of Multiple Myeloma Diagnostic Model Based on Logistic Regression in Clinical Laboratory.

BACKGROUND: Due to the insidious onset of multiple myeloma (MM), missed diagnosis and misdiagnosis have a serious impact on the health of MM patients. Simple, rapid, and valid laboratory screening is critical for MM clinical diagnosis. METHODS: We used routine laboratory tests to establish a simple, inexpensive, and non-invasive diagnostic model for MM based on logistic regression. In the retrospective analysis, a total of 273 newly diagnosed MM inpatients and 288 non-MM participants, from January 2016 to December 2018 in Beijing Chaoyang hospital, Capital Medical University, were divided into training set and validation set. Age, gender, and the related routine laboratory tests for MM, including albumin (ALB), globulin (GLB), lactate dehydrogenase (LDH), creatinine (Cr), calcium (Ca2+), hemoglobin (Hb) and platelet (PLT), were analyzed by multivariate logistic regression to develop a diagnostic model. RESULTS: A diagnostic model was calculated using the formula MM index=-((-18×gender-3×ALB-Hb)/10), based on the logistic regression. The MM index [22 (20 - 25)] of MM patients was significantly lower than that of non-MM [30 (29 - 31)] in the training set (p < 0.001). It showed an excellent diagnostic performance in diagnosing MM through a receiver operating characteristic (ROC) curve, and its corresponding sensitivity, specificity, and area under the curve (AUC) were 95.6%, 96.7%, and 0.982 (0.968, 0.997), respectively. At a diagnostic risk threshold of 28, the model identified MM with a sensitivity of 95.6% and a specificity of 98.1% by using independent validation data. There was a significant positive correlation (r = 0.845, p < 0.001) between the DS grading and the MM index among all the participants. CONCLUSIONS: The established diagnostic model of MM index can successfully identify newly diagnosed MM from healthy controls. The diagnostic model of MM index may also act as a predictor of the severity of MM without therapy.

Proteomics Analysis of E. angustifolia Seedlings Inoculated with Arbuscular Mycorrhizal Fungi under Salt Stress.

To reveal the mechanism of salinity stress alleviation by arbuscular mycorrhizal fungi (AMF), we investigated the growth parameter, soluble sugar, soluble protein, and protein abundance pattern of E. angustifolia seedlings that were cultured under salinity stress (300 mmol/L NaCl) and inoculated by Rhizophagus irregularis (RI). Furthermore, a label-free quantitative proteomics approach was used to reveal the stress-responsive proteins in the leaves of E. angustifolia. The result indicates that the abundance of 75 proteins in the leaves was significantly influenced when E. angustifolia was inoculated with AMF, which were mainly involved in the metabolism, signal transduction, and reactive oxygen species (ROS) scavenging. Furthermore, we identified chorismate mutase, elongation factor mitochondrial, peptidyl-prolyl cis-trans isomerase, calcium-dependent kinase, glutathione S-transferase, glutathione peroxidase, NADH dehydrogenase, alkaline neutral invertase, peroxidase, and other proteins closely related to the salt tolerance process. The proteomic results indicated that E. angustifolia seedlings inoculated with AMF increased the secondary metabolism level of phenylpropane metabolism, enhanced the signal transduction of Ca2+ and ROS scavenging ability, promoted the biosynthesis of protein, accelerated the protein folding, and inhibited the degradation of protein under salt stress. Moreover, AMF enhanced the synthesis of ATP and provided sufficient energy for plant cell activity. This study implied that symbiosis of halophytes and AMF has potential as an application for the improvement of saline-alkali soils.

Lactic acid bacterial inoculant effects on the vitamin content of alfalfa and Chinese leymus silage.

OBJECTIVE: Information regarding the vitamin content of silage is limited. This study investigated the changes in the vitamin content of alfalfa and Chinese leymus silages with or without a lactic acid bacterial inoculant. METHODS: Alfalfa at the early flowering stage and Chinese leymus at the full-bloom stage were harvested. The treatments for each forage type were control (deionized water only) and 1×106 colony-forming units (cfu) Lactobacillus plantarum (LP) g-1 FM. After 45 d ensiling, all silages were sampled for evaluating the vitamin content, fermentation quality and chemical composition. RESULTS: The LP inoculant decreased the pH and ammonia nitrogen content of the alfalfa and Chinese leymus silages and significantly (p &lt; 0.05) increased the lactic acid, acetic acid, propionic acid content and Flieg`s points. Prior to ensiling, the levels of five B-group vitamins (thiamin, riboflavin, niacin, pantothenic acid, pyridoxine) and α-tocopherol in alfalfa were significantly higher than those in Chinese leymus (p &lt; 0.01). Ensiling decreased the levels of the five B-group vitamins in both alfalfa and Chinese leymus while increasing the α-tocopherol content of Chinese leymus. The thiamin, riboflavin, niacin and pantothenic acid levels in the LP-treated silage were significantly (p &lt; 0.05) lower than those in the untreated silage for both forages. The α-tocopherol content in the LP-treated alfalfa silage was significantly (p &lt; 0.05) higher than that in the untreated alfalfa silage. There was no significant (p &gt; 0.05) difference in pyridoxine content between the untreated and LP-treated silages for both forages. CONCLUSION: With or without LP inoculation, the levels of the five B-group vitamins (thiamin, riboflavin, niacin, pantothenic acid, pyridoxine) in alfalfa and Chinese leymus decreased after 45 days of ensiling, while the α-tocopherol content of Chinese leymus increased. The LP inoculant improved the fermentation quality of both the alfalfa and Chinese leymus silages but increased the thiamin, riboflavin, niacin and pantothenic acid loss in the two forages after fermentation.

Uncertainty evaluation in clinical chemistry, immunoassay, hematology and coagulation analytes using only external quality assessment data.

BACKGROUND: Measurement uncertainty (MU) is a parameter associated with the result of a measurement that characterizes its dispersion. We report results for estimating MU following the application of a top-down procedure using only proficiency test data to establish uncertainty levels for various analytes. METHODS: Data were obtained from 142 laboratories participating in the Beijing Center for Clinical Laboratory (BCCL) proficiency testing/external quality assessment (PT/EQA) schemes. The 24-month study included six selected PT shipments to obtain estimates for 50th percentile (median) and 90th percentile MUs and to compare those estimates to usual analytic goals. The number of laboratory participants varied for each trial. The expanded uncertainty (U) was calculated using a cover factor of k=2 for a confidence interval of 95%. All reproducibility, method and laboratory biases came from the PT/EQA data. RESULTS: The median U (k=2) ranged from 3.2% (plasma sodium, indirect ion selective electrode) to 32.8% (triglycerides, free glycerol blanking) for clinical chemistry analyte means from participants in the same method group. Immunoassay analyte median U results ranged from 11.3% (CA125 tumor marker, Roche) to 33.8% (prostate-specific antigen [PSA], Abbott). The range for median U was 3.5% (red blood cell [RBC], Abx) to 30.3% (fibrinogen [FBG], other) for hematology and coagulation analytes. The MUs for most analytes satisfied quality requirements. CONCLUSIONS: The use of PT/EQA data, when available, provides an effective means for estimating uncertainties associated with quantitative measurements. Thus, medical laboratories can calculate their own MUs. Proficiency testing organizers can provide participants with an additional MU estimate using only EQA data, which may be updated at the end of each survey.