An integrative approach to protein sequence design through multiobjective optimization.

With recent methodological advances in the field of computational protein design, in particular those based on deep learning, there is an increasing need for frameworks that allow for coherent, direct integration of different models and objective functions into the generative design process. Here we demonstrate how evolutionary multiobjective optimization techniques can be adapted to provide such an approach. With the established Non-dominated Sorting Genetic Algorithm II (NSGA-II) as the optimization framework, we use AlphaFold2 and ProteinMPNN confidence metrics to define the objective space, and a mutation operator composed of ESM-1v and ProteinMPNN to rank and then redesign the least favorable positions. Using the two-state design problem of the foldswitching protein RfaH as an in-depth case study, and PapD and calmodulin as examples of higher-dimensional design problems, we show that the evolutionary multiobjective optimization approach leads to significant reduction in the bias and variance in RfaH native sequence recovery, compared to a direct application of ProteinMPNN. We suggest that this improvement is due to three factors: (i) the use of an informative mutation operator that accelerates the sequence space exploration, (ii) the parallel, iterative design process inherent to the genetic algorithm that improves upon the ProteinMPNN autoregressive sequence decoding scheme, and (iii) the explicit approximation of the Pareto front that leads to optimal design candidates representing diverse tradeoff conditions. We anticipate this approach to be readily adaptable to different models and broadly relevant for protein design tasks with complex specifications.

VISTA antibody-loaded Fe3O4@TiO2 nanoparticles for sonodynamic therapy-synergistic immune checkpoint therapy of pancreatic cancer.

Breaking the poor permeability of immune checkpoint inhibitors (ICIs) caused by the stromal barrier and reversing the immunosuppressive microenvironment are significant challenges in pancreatic cancer immunotherapy. In this study, we synthesized core-shell Fe3O4@TiO2 nanoparticles to act as carriers for loading VISTA monoclonal antibodies to form Fe3O4@TiO2@VISTAmAb (FTV). The nanoparticles are designed to target the overexpressed ICIs VISTA in pancreatic cancer, aiming to improve magnetic resonance imaging-guided sonodynamic therapy (SDT)-facilitated immunotherapy. Laser confocal microscopy and flow cytometry results demonstrate that FTV nanoparticles are specifically recognized and phagocytosed by Panc-2 cells. In vivo experiments reveal that ultrasound-triggered TiO2 SDT can induce tumor immunogenic cell death (ICD) and recruit T-cell infiltration within the tumor microenvironment by releasing damage-associated molecular patterns (DAMPs). Furthermore, ultrasound loosens the dense fibrous stroma surrounding the pancreatic tumor and increases vascular density, facilitating immune therapeutic efficiency. In summary, our study demonstrates that FTV nanoparticles hold great promise for synergistic SDT and immunotherapy in pancreatic cancer.

Temperature-Dependent Fold-Switching Mechanism of the Circadian Clock Protein KaiB.

The oscillator of the cyanobacterial circadian clock relies on the ability of the KaiB protein to switch reversibly between a stable ground-state fold (gsKaiB) and an unstable fold-switched fold (fsKaiB). Rare fold-switching events by KaiB provide a critical delay in the negative feedback loop of this post-translational oscillator. In this study, we experimentally and computationally investigate the temperature dependence of fold switching and its mechanism. We demonstrate that the stability of gsKaiB increases with temperature compared to fsKaiB and that the Q10 value for the gsKaiB → fsKaiB transition is nearly three times smaller than that for the reverse transition. Simulations and native-state hydrogen-deuterium exchange NMR experiments suggest that fold switching can involve both subglobally and near-globally unfolded intermediates. The simulations predict that the transition state for fold switching coincides with isomerization of conserved prolines in the most rapidly exchanging region, and we confirm experimentally that proline isomerization is a rate-limiting step for fold switching. We explore the implications of our results for temperature compensation, a hallmark of circadian clocks, through a kinetic model.

An integrative approach to protein sequence design through multiobjective optimization.

With recent methodological advances in the field of computational protein design, in particular those based on deep learning, there is an increasing need for frameworks that allow for coherent, direct integration of different models and objective functions into the generative design process. Here we demonstrate how evolutionary multiobjective optimization techniques can be adapted to provide such an approach. With the established Non-dominated Sorting Genetic Algorithm II (NSGA-II) as the optimization framework, we use AlphaFold2 and ProteinMPNN confidence metrics to define the objective space, and a mutation operator composed of ESM-1v and ProteinMPNN to rank and then redesign the least favorable positions. Using the multistate design problem of the foldswitching protein RfaH as an in-depth case study, we show that the evolutionary multiobjective optimization approach leads to significant reduction in the bias and variance in RfaH native sequence recovery, compared to a direct application of ProteinMPNN. We suggest that this improvement is due to three factors: (i) the use of an informative mutation operator that accelerates the sequence space exploration, (ii) the parallel, iterative design process inherent to the genetic algorithm that improves upon the ProteinMPNN autoregressive sequence decoding scheme, and (iii) the explicit approximation of the Pareto front that leads to optimal design candidates representing diverse tradeoff conditions. We anticipate this approach to be readily adaptable to different models and broadly relevant for protein design tasks with complex specifications.

Development of a QuEChERS-HPLC-FLD Procedure for the Simultaneous Detection of Residues of Florfenicol, Its Metabolite Florfenicol Amine, and Three Fluoroquinolones in Eggs.

A method utilizing high-performance liquid chromatography-fluorescence detection (HPLC-FLD) has been developed and refined for the simultaneous detection of florfenicol (FF) and its metabolite florfenicol amine (FFA) along with three fluoroquinolone (ciprofloxacin (CIP), enrofloxacin (ENR), and sarafloxacin (SAR)) residues in different parts of eggs (whole egg, egg yolk, and egg albumen). The QuEChERS ("Quick, easy, cheap, effective, rugged, and safe") procedure utilized 0.1 M disodium EDTA solution, water, and acetonitrile as extractants; sodium sulfate, sodium chloride, and trisodium citrate as dehydrating salts; and N-propylethylenediamine and C18 as adsorbents. A dual-channel FLD method was utilized to analyze the target compounds using an XBridge BEH C18 chromatographic column (4.6 mm × 150 mm, 5 µm). The mobile phase was employed isocratically using a solution of 0.01 M sodium dihydrogen phosphate, 0.005 M sodium dodecyl sulfate, and 0.1% triethylamine (pH 4.8) in combination with acetonitrile at a ratio of 65:35 (V/V). The limits of detection (LOD) and quantification (LOQ) of the analytes ranged from 0.03 to 1.5 µg/kg and from 0.1 to 5.0 µg/kg, respectively. The recoveries of the analytes in the blank egg samples ranged from 71.9% to 94.8% when reference standard concentrations of the LOQ, half of the maximum residual limit (MRL), MRL, and twice the MRL were added. The parameters of the presented protocol were validated and subsequently applied to the analysis of real samples, demonstrating the applicability and reliability of the method.

Fetal Hyperthyroidism with Maternal Hypothyroidism: Two Cases of Intrauterine Therapy.

Fetal hyperthyroidism can occur secondary to maternal autoimmune hyperthyroidism. The thyroid-stimulating hormone receptor antibody (TRAb) transferred from the mother to the fetus stimulates the fetal thyroid and causes fetal thyrotoxicosis. Fetuses with this condition are difficult to detect, especially after maternal Graves disease therapy. Here, we present two cases of fetal hyperthyroidism with maternal hypothyroidism and review the assessment and intrauterine therapy for fetal hyperthyroidism. Both women were referred at 22+ and 23+ weeks of gestation with abnormal ultrasound findings, including fetal heart enlargement, pericardial effusion, and fetal tachycardia. Both women had a history of Graves disease while in a state of hypothyroidism with a high titer of TRAb. A sonographic examination showed a diffusely enlarged fetal thyroid with abundant blood flow. Invasive prenatal testing revealed no significant chromosomal aberration. Low fetal serum TSH and high TRAb levels were detected in the cord blood. Fetal hyperthyroidism was considered, and maternal oral methimazole (MMI) was administered as intrauterine therapy, with the slowing of fetal tachycardia, a reduction in fetal heart enlargement, and thyroid hyperemia. During therapy, maternal thyroid function was monitored, and the dosage of maternal levothyroxine was adjusted accordingly. Both women delivered spontaneously at 36+ weeks of gestation, and neonatal hyperthyroidism was confirmed in both newborns. After methimazole and propranolol drug treatment with levothyroxine for 8 and 12 months, both babies became euthyroid with normal growth and development.

Association between index-ring finger length ratio and polymorphisms of 6 phalange-bone development related genes / 解剖学报

Objective To investigate the association of 13 single nucleotide polymorphism(SNP)sites in 6 phalange-bone development related genes[fibroblast growth factor receptor 2(FGFR2),indian hedgehog signaling molecule(IHH),Msh homeobox 1(MSX1),Runx family transcription factor 2(RUNX2),SRY-box transcription factor 9(SOX9),Wnt family member 5A(WNT5A)]with human index-ring finger length ratio(2D∶4D).Methods Digital cameras were used to take frontal photographs of the hands of 731 college students(358 males and 373 females)in Ningxia,and image analysis software was used to mark anatomical points and measure finger lengths of index(2th)and ring(4th);genotyping of 13 SNP sites(rs1047057,rs755793,rs41258305,rs3731881,rs3100776,rs12532,rs3821949,rs45585135,rs3749863,rs1042667,rs12601701,rs1829556,rs3732750)for 6 genes by multiplex PCR;One-Way ANOVA or independent sample t-test indirectly assessed the association between 2D∶4D and 13 SNP sites.Results Both left and right hand 2D∶4D were significantly higher in females than males in Ningxia college students(all P<0.01);no statistically significant differences in genotype and allele frequencies of the 13 SNP sites among different sexes(all P>0.05);among different sexes,male left hand 2D∶4D was significantly associated with the genotype of SOX9 gene rs12601701 site(P<0.05)and right hand 2D∶4D was significantly associated with the genotype of WNT5A gene rs1829556 site(P<0.05);the female right hand 2D∶4D was significantly associated with the MSX1 gene rs12532(P<0.01)and rs3821949(P<0.05)sites genotypes.Conclusion SOX9(rs12601701),WNT5A(rs1829556)and MSX1(rs12532 and rs3821949)gene polymorphisms may be associated with the formation of 2D∶4D in Ningxia population.

Effect of LPCAT1 on biological behavior of cervical cancer based on β-catenin/Slug signaling pathway / 临床与实验病理学杂志

Purpose To observation the relationship be-tween the β-catenin/Slug signal specific inhibitor FH535 and EMT,and to explore the role of LPCAT1 in regulating the inva-sion,metastasis,and growth of cervical cancer cells.Methods Hela cells were transfected with sh-NC and sh-LPCAT1,and SiHa cells were transfected with Vector group and LPCAT1 over-expression plasmid.SiHa cells were divided into control group(Con),LPCAT1 group,LPCAT1+FH535 group and FH535 group.The proliferation of cervical cancer cells was detected by CCK-8 analysis and colony formation test.The metastasis and invasion ability of cervical cancer cells were detected by wound healing test and Transwell test.Western blot was used to analyze the expression of LPCAT1,β-catenin/Slug signaling pathway and EMT-related proteins in cells.Results Compared with Vector group,the cell viability,colony number,migration and invasion number of SiHa cells in LPCAT1 group increased signif-icantly(P＜0.05).Compared with sh-NC group,the cell via-bility,colony number,migration and invasion number of Hela cells in sh-LPCAT1 group decreased significantly(P＜0.05).Compared with LPCAT1 group,the levels of Wnt4(1.18±0.05 vs 0.80±0.06),β-catenin(1.05±0.08 vs 0.77±0.05),Slug(1.13±0.06 vs 0.28±0.02),Cyclin D1(0.99±0.06 vs 0.44±0.02),N-cadherin(0.91±0.07 vs 0.46±0.03)and vimentin(0.95±0.06 vs 0.49±0.03)in SiHa cells in LPCAT1+FH535 group decreased significantly(P＜0.05),and the level of E-cadherin(0.44±0.03 vs 0.58±0.03)in-creased significantly(P＜0.05).In addition,compared with LPCAT1 group,the number of colonies(224±15 vs 146±11),migration(85±3vs51±4)and invasive(166±10 vs 90±5)cells of SiHa cells in LPCAT1+FH535 group decreased signifi-cantly(P＜0.05).Conclusion The increase of LPCAT1 ex-pression may promote the metastasis and progress of CC by acti-vating β-catenin/Slug signaling pathway,and LPCAT1 may be a potential marker for predicting CC metastasis.

Association between index finger and ring finger length ratios and polymorphism of homeobox A11 gene locus among Ningxia college students / 解剖学报

Objective To investigate the association between the index finger and ring finger length ratio (2D ∶ 4D) and of four loci (rs6461992‚ rs6968828‚ rs7801581‚ rs17427875) polymorphism of homeobox (HOX) A11 gene among Ningxia college students. Methods Digit camera was used to collect frontal hand photos of 667 Han college students (348 males and 319 females) from Ningxia province; Image analysis software was used to mark the anatomical points and measure finger lengths of the index and ring fingers of both hands; multiplex PCR was used to detect each locus polymorphisms of HOXA11 gene; statistical software was used to compare and analyze the differences and associations of 2D ∶4D and gene polymorphisms between different genders. Results Among Ningxia Han college students‚ both left hand and right hand 2D ∶ 4D were significantly higher in females than those of in males (all P< 0. 05)‚ and there were no significant sex differences in right-left hand 2D ∶4D; the genotypes and allele frequencies of rs7801581 locus of HOXA11 gene differed significantly between genders (all P < 0. 05)‚ and none of the other locus polymorphisms showed any significant sex differences; only female left hand 2D ∶4D was significantly associated with rs6461992 locus genotype in the relationship between 2D ∶4D and HOXA11 polymorphisms (P<0. 05). Conclusion There were significant sex differences in 2D ∶ 4D among Han college students in Ningxia‚ and the rs6461992 locus polymorphism of HOXA11 gene may be associated with the formation of 2D ∶4D in females.

Analysis of amino acid and protein components of commercial swim-bladders / 中成药

AIM To study the amino acids and proteins in 16 batches of commercial fish swim-bladders with different origins.METHODS A high performance liquid chromatography method based on pre-column derivatization using 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate(AQC)was developed for the determination of contents and components of 17 amino acids in fish swim-bladders.Sodium dodecyl sulfate-polyacrylamide gel electrophoresis(SDS-PAGE)was performed to analyze the molecular weight distribution of proteins from different fish swim-bladders,and proteins in fish swim-bladders were identified by proteomics method.RESULTS The result showed that the determination of 17 amino acids had a good linear relationship(R2≥0.998 0).The average recovery rate was 85.62%-109.60%and the relative standard deviations of precision,stability and repeatability were less than 3.5%.The total content of the 17 amino acids in 16 batches of fish swim-bladders ranged from 468.31 mg/g to 620.05 mg/g.A total of 688 proteins including 11 collagens were identified from 16 batches of fish swim-bladder samples and a plenty of low-abundance proteins at 52-95 kDa were also detected in fish swim-bladders by SDS-PAGE.CONCLUSION This study provides a good reference for the quality evaluation and further utilization of fish swim-bladders.

Rapid and Non-Invasive Assessment of Texture Profile Analysis of Common Carp (Cyprinus carpio L.) Using Hyperspectral Imaging and Machine Learning.

Hyperspectral imaging (HSI) has been applied to assess the texture profile analysis (TPA) of processed meat. However, whether the texture profiles of live fish muscle could be assessed using HSI has not been determined. In this study, we evaluated the texture profile of four muscle regions of live common carp by scanning the corresponding skin regions using HSI. We collected skin hyperspectral information from four regions of 387 scaled and live common carp. Eight texture indicators of the muscle corresponding to each skin region were measured. With the skin HSI of live common carp, six machine learning (ML) models were used to predict the muscle texture indicators. Backpropagation artificial neural network (BP-ANN), partial least-square regression (PLSR), and least-square support vector machine (LS-SVM) were identified as the optimal models for predicting the texture parameters of the dorsal (coefficients of determination for prediction (rp) ranged from 0.9191 to 0.9847, and the root-mean-square error for prediction ranged from 0.1070 to 0.3165), pectoral (rp ranged from 0.9033 to 0.9574, and RMSEP ranged from 0.2285 to 0.3930), abdominal (rp ranged from 0.9070 to 0.9776, and RMSEP ranged from 0.1649 to 0.3601), and gluteal (rp ranged from 0.8726 to 0.9768, and RMSEP ranged from 0.1804 to 0.3938) regions. The optimal ML models and skin HSI data were employed to generate visual prediction maps of TPA values in common carp muscles. These results demonstrated that skin HSI and the optimal models can be used to rapidly and accurately determine the texture qualities of different muscle regions in common carp.

Network pharmacology-guided and TCM theory-supported in vitro and in vivo component identification of Naoluoxintong.

Naoluoxintong (NLXT) has been used to treat ischemic stroke (IS) in China for more than two hundred years. However, the pharmacodynamic material basis of NLXT has not been fully studied. Under the guidance of the former network pharmacological analysis, a rapid and reliable method combining UPLC-Q-TOF-MSE with the novel informatics UNIFI™ platform was established which was used to study the composition of NLXT and its prototype components and metabolites in vivo. A total of 102 compounds were identified. 13 compounds were sourced from "Monarch herb", mainly involving flavonoids and their glycosides. 54 compounds were sourced from "Minister herb", mainly involving triterpenoid saponins, organic acids and lactones. 11 compounds were from the "Assistant herb", mostly containing citric acid and esters of citric acid. 24 compounds were from the "Guide herb", mostly including flavonoids and their glycosides, organic acids and lactones. Moreover, 24 prototype components and 30 metabolites were detected, and in vivo transformation pathways for different types of chemical components were provided. This is a comprehensive report on the identification of major chemical components in NLXT and metabolic components in rats by UPLC-Q-TOF-MS combined with UNIFI platform under the guidance of network pharmacology, which is helpful for the quality control of NLXT and the study of quality markers.

Determining subunit-subunit interaction from statistics of cryo-EM images: observation of nearest-neighbor coupling in a circadian clock protein complex.

Biological processes are typically actuated by dynamic multi-subunit molecular complexes. However, interactions between subunits, which govern the functions of these complexes, are hard to measure directly. Here, we develop a general approach combining cryo-EM imaging technology and statistical modeling and apply it to study the hexameric clock protein KaiC in Cyanobacteria. By clustering millions of KaiC monomer images, we identify two major conformational states of KaiC monomers. We then classify the conformational states of (>160,000) KaiC hexamers by the thirteen distinct spatial arrangements of these two subunit states in the hexamer ring. We find that distributions of the thirteen hexamer conformational patterns for two KaiC phosphorylation mutants can be fitted quantitatively by an Ising model, which reveals a significant cooperativity between neighboring subunits with phosphorylation shifting the probability of subunit conformation. Our results show that a KaiC hexamer can respond in a switch-like manner to changes in its phosphorylation level.

Prognosis of Patients With Triple-negative Breast Cancer: A Population-based Study From SEER Database.

BACKGROUND: Triple-negative breast cancer (TNBC) was a particularly aggressive subtype of breast cancer associated with poor prognosis. This retrospective study was conducted to investigate the clinical features, prognostic factors, and benefits of surgery of patients with TNBC. METHODS: From 2010 to 2015, 33654 female patients with TNBC were obtained from the Surveillance, Epidemiology, and End Results (SEER) database. The patients were randomly divided into the training and validation cohorts. Univariate and multivariable cox regression were performed to identify prognostic factors, based on which a nomogram was constructed. Validation of the nomogram was assessed by concordance index (c-index) and calibration curves. Survival curves were plotted according to metastatic burdens and risk groups differentiated by nomogram. RESULTS: Patients of younger age (<65 years old), white race, married status, lower grade, lower TNM stage and primary tumor surgery tended to have better outcome. The C-index and calibration curves displayed high discrimination in the training and validation sets (C-index 0.794 and 0.793, respectively), indicating suitable external performance of the nomogram model. Patients of bone-only metastases as well as bone and liver metastases showed superior cancer-specific survival (CSS) time if surgery of primary tumor was performed. Besides, patients of all risk groups showed better CSS when receiving surgery. CONCLUSION: This study provided population-based prognostic analysis in patients with TNBC and constructed a predicting nomogram with a robust discrimination. The findings of potential benefit of surgery to CSS would shed some lights on the treatment tactics of patients with TNBC.

The development trend of scientific research in the field of maternal and child health in the new era in China / 中国实用护理杂志

This commentary summarized the development trend of scientific research in the field of maternal and child health in China, based on the requirements of scientific innovation in the field of health care in China and the development goals of maternal and child health in the next ten years. Scientific research should be based on China's reality and solve China's problems; based on evidence-based evidence and promote its application and promotion; conduct interdisciplinary cooperation and promote the integrated development of disciplines; focus on academic frontiers and broaden international horizons.

BRICS report of 2021: The distribution and antimicrobial resistance profile of clinical bacterial isolates from blood stream infections in China / 中华临床感染病杂志

Objective:To report the results of national surveillance on the distribution and antimicrobial resistance profile of clinical bacterial isolates from bloodstream infections in China in 2021.Methods:The clinical bacterial strains isolated from blood culture from member hospitals of Blood Bacterial Resistant Investigation Collaborative System (BRICS) were collected during January 2021 to December 2021. Antibiotic susceptibility tests were conducted by agar dilution or broth dilution methods recommended by Clinical Laboratory Standards Institute (CLSI). WHONET 5.6 was used to analyze data.Results:During the study period, 11 013 bacterial strains were collected from 51 hospitals, of which 2 782 (25.3%) were Gram-positive bacteria and 8 231 (74.7%) were Gram-negative bacteria. The top 10 bacterial species were Escherichia coli (37.6%), Klebsiella pneumoniae (18.9%), Staphylococcus aureus (9.8%), coagulase-negative Staphylococci (6.3%), Pseudomonas aeruginosa (3.6%), Enterococcus faecium (3.6%), Acinetobacter baumannii (2.8%), Enterococcus faecalis (2.7%), Enterobacter cloacae (2.5%) and Klebsiella spp (2.1%). The prevalence of methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant coagulase-negative Staphylococcus aureus were 25.3% and 76.8%, respectively. No glycopeptide- and daptomycin-resistant Staphylococci was detected; more than 95.0% of Staphylococcus aureus were sensitive to ceftobiprole. No vancomycin-resistant Enterococci strains were detected. The rates of extended spectrum B-lactamase (ESBL)-producing isolated in Escherichia coli, Klebsiella pneumoniae and Proteus mirabilis were 49.6%, 25.5% and 39.0%, respectively. The prevalence rates of carbapenem-resistance in Escherichia coli and Klebsiella pneumoniae were 2.2% and 15.8%, respectively; 7.9% of carbapenem-resistant Klebsiella pneumoniae was resistant to ceftazidime/avibactam combination. Ceftobiprole demonstrated excellent activity against non-ESBL-producing Escherichia coli and Klebsiella pneumoniae. Aztreonam/avibactam was highly active against carbapenem-resistant Escherichia coli and Klebsiella pneumoniae. The prevalence rate of carbapenem-resistance in Acinetobacter baumannii was 60.0%, while polymyxin and tigecycline showed good activity against Acinetobacter baumannii (5.5% and 4.5%). The prevalence of carbapenem-resistance in Pseudomonas aeruginosa was 18.9%. Conclusions:The BRICS surveillance results in 2021 shows that the main pathogens of blood stream infection in China are gram-negative bacteria, in which Escherichia coli is the most common. The MRSA incidence shows a further decreasing trend in China and the overall prevalence of vancomycin-resistant Enterococci is low. The prevalence of Carbapenem-resistant Klebsiella pneumoniae is still on a high level, but the trend is downwards.

Analytical performance verification protocols and specifications of CD34 +cell enumeration by flow cytometry / 中华检验医学杂志

Objective:To investigate the analytical performance verification protocols and performance specifications of CD34+cell enumeration by flow cytometry for clinical laboratories.Methods:According to international guidelines and National Health Standard of China, we designed the performance verification protocols of CD34 +cell enumeration (including percent count and absolute count) by flow cytometry. Four quality assessment materials, three leukapheresis products and three samples of peripheral blood were selected to verify the precision, linearity, carryover, trueness and accuracy of FACSCanto Ⅱ measurement system, and the assessment criterion was set according to the detection technologies of clinical laboratories. Results:The CVs of intra-run precision of percent count and absolute count were 2.5% to 8.9% and 3.0% to 9.0%; the CVs of inter-run precision were 2.8% to 10.5% and 3.8% to 9.9%, respectively. The slopes of linearity regression equation of low range (3.6/μl to 123.6/μl) and high range (113.2/μl to 1196.3/μl) were 0.993 2 and 0.965 2, and R2 were 0.999 6 and 0.993 9, and the biases were -8.67% to 0.22%. The carryover of percent and absolute count were 0.07% and 0.00%. When percent count≤0.2% or absolute count≤20/μl, the absolute biases of trueness were in the range of ±0.006% or ±0.5/μl, and the absolute biases of accuracy were in the range of ±0.02% or ±0.9/μl; when percent count>0.2% or absolute count>20/μl, the relative biases of trueness were in the range of ±5.65%, and the relative biases of accuracy were in the range of ±8.19%. The verification results met the assessment criterion set in this study. Conclusions:The performance verification protocols and assessment criterion formulated in this study not only conform to the recommendations of domestic and foreign guidelines, but also conform to state of the detection technologies of native clinical laboratories, which can be taken as a reference of performance verification for clinical laboratories.

Body water percentage from childhood to old age

Total body water (TBW) increases with growth, but the body water percentage (TBW%) decreases with aging. The objective of our study was to delineate TBW% in males and females by bioelectrical impedance analysis (BIA) from early childhood to old age. Methods: We enrolled 545 participants aged 3 to 98 years (258 male, 287 female). Among the participants, 256 had a normal weight and 289 were overweight. The TBW was measured by BIA, and TBW% was derived by dividing the TBW (L) value by body weight (kg). For analysis, we divided participants into the four age groups of 3–10, 11–20, 21–60, and ≥61 years. Results: In normal-weight subjects, the TBW% was similar at 62% between males and females in the 3–10-year group. It remained unchanged in males until and through adult life, then decreased to 57% in the ≥61-year group. In normal-weight female subjects, the TBW% decreased to 55% in the 11–20-year group, remained relatively unaltered in the 21–60-year group, then decreased to 50% in the ≥61-year group. In overweight subjects, the TBW% values in males, as well as females, were significantly lower as compared to those with normal weight. Conclusion: Our study showed that the TBW% in normal-weight males changes very little from early childhood to adult life compared to that of females, who showed a decrease in TBW% during the pubertal years. In normal-weight subjects of both sexes, the TBW% decreased after the age of 60 years. Overweight subjects had significantly lower TBW% as compared to those with normal weight.