Polymersomes in Drug Delivery─From Experiment to Computational Modeling.

Polymersomes, composed of amphiphilic block copolymers, are self-assembled vesicles that have gained attention as potential drug delivery systems due to their good biocompatibility, stability, and versatility. Various experimental techniques have been employed to characterize the self-assembly behaviors and properties of polymersomes. However, they have limitations in revealing molecular details and underlying mechanisms. Computational modeling techniques have emerged as powerful tools to complement experimental studies and enabled researchers to examine drug delivery mechanisms at molecular resolution. This review aims to provide a comprehensive overview of the state of the art in the field of polymersome-based drug delivery systems, with an emphasis on insights gained from both experimental and computational studies. Specifically, we focus on polymersome morphologies, self-assembly kinetics, fusion and fission, behaviors in flow, as well as drug encapsulation and release mechanisms. Furthermore, we also identify existing challenges and limitations in this rapidly evolving field and suggest possible directions for future research.

Enhancing lactose recognition of a key enzyme in 2'-fucosyllactose synthesis: α-1,2-fucosyltransferase.

BACKGROUND: 2'-Fucosyllactose, a representative oligosaccharide in human milk, is an emerging and promising food and pharmaceutical ingredient due to its powerful health benefits, such as participating in immune regulation, regulation of intestinal flora, etc. To enable economically viable production of 2'-fucosyllactose, different biosynthesis strategies using precursors and pathway enzymes have been developed. The α-1,2-fucosyltransferases are an essential part involved in these strategies, but their strict substrate selectivity and unsatisfactory substrate tolerance are one of the key roadblocks limiting biosynthesis. RESULTS: To tackle this issue, a semi-rational manipulation combining computer-aided designing and screening with biochemical experiments were adopted. The mutant had a 100-fold increase in catalytic efficiency compared to the wild-type. The highest 2'-fucosyllactose yield was up to 0.65 mol mol-1 lactose with a productivity of 2.56 g mL-1  h-1 performed by enzymatic catalysis in vitro. Further analysis revealed that the interactions between the mutant and substrates were reduced. The crucial contributions of wild-type and mutant to substrate recognition ability were closely related to their distinct phylotypes in terms of amino acid preference. CONCLUSION: It is envisioned that the engineered α-1,2-fucosyltransferase could be harnessed to relieve constraints imposed on the bioproduction of 2'-fucosyllactose and lay a theoretical foundation for elucidating the substrate recognition mechanisms of fucosyltransferases. © 2022 Society of Chemical Industry.

Relationship between dry skin and pressure injury in older patients: A multicentre cross-sectional survey in China.

Dry skin and pressure injuries in older persons have become global health care problems. This was a multicentre, prospective cross-sectional study in 44 hospitals and 8 long term care institutions from 20 provinces, autonomous regions and municipalities in China and aimed to explore the relationship between the two skin problems in older patients. We mainly found 11 602 cases with dry skin and 1076 cases with pressure injuries in a total of 33 769 valid participants. The overall prevalence of dry skin and pressure injuries was 34.4% (95% confidence interval [CI] 33.9-34.9) and 3.1% (95% CI 2.9-3.3). Stage 2+ pressure injuries were the most (32.9%), followed by stage 1 (32.4%). The patients with dry skin had more pressure injuries than ones without dry skin (50.0% vs 33.9%). The patients with very severe and severe dry skin had more pressure injury risk (OR 2.22 and 1.90) and more stage 2+ pressure injury risk (OR 2.83 and 1.63). Other nine predictors associated with overall pressure injuries and stage 2+ pressure injuries. The area under receiver operating characteristic (ROC) curve of the predictive models of overall pressure injuries and stage 2+ pressure injuries were 0.89 (95% CI 0.88-0.90) and 0.91 (95% CI 0.90-0.92), respectively.

A Four-Step Enzymatic Cascade for Efficient Production of L-Phenylglycine from Biobased L-Phenylalanine.

Enantiopure amino acids are of particular interest in the agrochemical and pharmaceutical industries. Here, we report a multi-enzyme cascade for efficient production of L-phenylglycine (L-Phg) from biobased L-phenylalanine (L-Phe). We first attempted to engineer Escherichia coli for expressing L-amino acid deaminase (LAAD) from Proteus mirabilis, hydroxymandelate synthase (HmaS) from Amycolatopsis orientalis, (S)-mandelate dehydrogenase (SMDH) from Pseudomonas putida, the endogenous aminotransferase (AT) encoded by ilvE and L-glutamate dehydrogenase (GluDH) from E. coli. However, 10 mM L-Phe only afforded the synthesis of 7.21±0.15 mM L-Phg. The accumulation of benzoylformic acid suggested that the transamination step might be rate-limiting. We next used leucine dehydrogenase (LeuDH) from Bacillus cereus to bypass the use of L-glutamate as amine donor, and 40 mM L-Phe gave 39.97±3.84 mM (6.04±0.58 g/L) L-Phg, reaching 99.9 % conversion. In summary, this work demonstrates a concise four-step enzymatic cascade for L-Phg synthesis from biobased L-Phe, with a potential for future industrial applications.

Serum creatinine as a biomarker for dystrophinopathy: a cross-sectional and longitudinal study.

BACKGROUND: Dystrophinopathy, a common neuromuscular disorder, includes Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD). Many researches are currently ongoing to develop curative approaches, which results in an urgent need for biomarkers of disease progression and treatment response. This study investigated whether the serum creatinine (SCRN) level can be used as a biomarker of disease progression in dystrophinopathy. METHODS: We enrolled 377 male patients with dystrophinopathy and 520 male non-dystrophinopathy controls in a cross-sectional study. From this cohort, 113 follow-up patients were enrolled in a longitudinal study. Patients' demographic information, motor function, muscle fatty infiltration, and muscle dystrophin levels were evaluated. We investigated correlations between these parameters and SCRN levels, and determined changes in SCRN levels with maturation and with motor function changes. RESULTS: Our results showed SCRN levels correlated with motor function (FDR < 0.001) and timed test results (FDR between < 0.001-0.012), as well as with muscle fatty infiltration (FDR < 0.001) and dystrophin levels (FDR = 0.015 and 0.001). SCRN levels increased with maturation in control individuals; it slowly increased with maturation in patients with BMD but decreased generally with maturation in patients with DMD. The longitudinal study further demonstrated that SCRN levels were associated with motor function. CONCLUSIONS: These findings indicated that the SCRN level is a promising biomarker for assessing disease progression in dystrophinopathy and could be used as a potential outcome measure in clinical trials.

Homozygous NOTCH3 p.R587C mutation in Chinese patients with CADASIL: a case report.

BACKGROUND: Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is an inherited small vessel disease caused by mutations in NOTCH3 gene with remarkable phenotypic heterogeneity. Cases of CADASIL associated with homozygous NOTCH3 mutations are rare and subsequently understudied. In this study, we investigate the genetic and phenotypic features within patients of CADASIL with homozygous NOTCH3 mutations. CASE PRESENTATION: We recruited two affected individuals with CADASIL from a mainland Chinese family. The proband (Patient 1), a 60-year-old male, presented with slow progressive gait instability, severe cognitive impairment, and emotional disorder for more than 2 years with a history of ischemic stroke and hypertension. His younger brother (Patient 2) presented with apparent gait difficulties, dysarthria as well as cognitive decline at 59 years old. Brain magnetic resonance imaging (MRI) showed diffused white matter lesions involving bilateral periventricular white matter, semioval center region, and anterior temporal lobes. Molecular genetic testing identified a homozygous variant, c.1759C > T (p.R587C), in NOTCH3 gene in both patients. Pathological analysis revealed granular osmiophilic material (GOM) deposits in small arterial walls of skin from the proband. The diagnosis of CADASIL was confirmed. CONCLUSIONS: Our cases of CADASIL with homozygous mutation c.1759C > T (p.R587C) in NOTCH3 share similar manifestation to the patients with heterozygous same mutation reported previously. Other than genetic factors, vascular risk factors or environmental factors might contribute to the phenotypic variation of CADASIL.

Engraftment of human induced pluripotent stem cell-derived myogenic progenitors restores dystrophin in mice with duchenne muscular dystrophy.

BACKGROUND: Duchenne muscular dystrophy (DMD) is a devastating genetic muscular disorder with no effective treatment that is caused by the loss of dystrophin. Human induced pluripotent stem cells (hiPSCs) offer a promising unlimited resource for cell-based therapies of muscular dystrophy. However, their clinical applications are hindered by inefficient myogenic differentiation, and moreover, the engraftment of non-transgene hiPSC-derived myogenic progenitors has not been examined in the mdx mouse model of DMD. METHODS: We investigated the muscle regenerative potential of myogenic progenitors derived from hiPSCs in mdx mice. The hiPSCs were transfected with enhanced green fluorescent protein (EGFP) vector and defined as EGFP hiPSCs. Myogenic differentiation was performed on EGFP hiPSCs with supplementary of basic fibroblast growth factor, forskolin, 6-bromoindirubin-3'-oxime as well as horse serum. EGFP hiPSCs-derived myogenic progenitors were engrafted into mdx mice via both intramuscular and intravenous injection. The restoration of dystrophin expression, the ratio of central nuclear myofibers, and the transplanted cells-derived satellite cells were accessed after intramuscular and systemic transplantation. RESULTS: We report that abundant myogenic progenitors can be generated from hiPSCs after treatment with these three small molecules, with consequent terminal differentiation giving rise to mature myotubes in vitro. Upon intramuscular or systemic transplantation into mdx mice, these myogenic progenitors engrafted and contributed to human-derived myofiber regeneration in host muscles, restored dystrophin expression, ameliorated pathological lesions, and seeded the satellite cell compartment in dystrophic muscles. CONCLUSIONS: This study demonstrates the muscle regeneration potential of myogenic progenitors derived from hiPSCs using non-transgenic induction methods. Engraftment of hiPSC-derived myogenic progenitors could be a potential future therapeutic strategy to treat DMD in a clinical setting.

Overexpression of an endogenous raw starch digesting mesophilic α-amylase gene in Bacillus amyloliquefaciens Z3 by in vitro methylation protocol.

BACKGROUND: Mesophilic α-amylases function effectively at low temperatures with high rates of catalysis and require less energy for starch hydrolysis. Bacillus amyloliquefaciens is an essential producer of mesophilic α-amylases. However, because of the existence of the restriction-modification system, introducing exogenous DNAs into wild-type B. amyloliquefaciens is especially tricky. RESULTS: α-Amylase producer B. amyloliquefaciens strain Z3 was screened and used as host for endogenous α-amylase gene expression. In vitro methylation was performed in recombinant plasmid pWB980-amyZ3. With the in vitro methylation, the transformation efficiency was increased to 0.96 × 102 colony-forming units µg-1 plasmid DNA. A positive transformant BAZ3-16 with the highest α-amylase secreting capacity was chosen for further experiments. The α-amylase activity of strain BAZ3-16 reached 288.70 ± 16.15 U mL-1 in the flask and 386.03 ± 16.25 U mL-1 in the 5-L stirred-tank fermenter, respectively. The Bacillus amyloliquefaciens Z3 expression system shows excellent genetic stability and high-level extracellular production of the target protein. Moreover, the synergistic interaction of AmyZ3 with amyloglucosidase was determined during the hydrolysis of raw starch. The hydrolysis degree reached 92.34 ± 3.41% for 100 g L-1 raw corn starch and 81.30 ± 2.92% for 100 g L-1 raw cassava starch after 24 h, respectively. CONCLUSION: Methylation of the plasmid DNA removes a substantial barrier for transformation of B. amyloliquefaciens strain Z3. Furthermore, the exceptional ability to hydrolyze starch makes α-amylase AmyZ3 and strain BAZ3-16 valuable in the starch industry. © 2020 Society of Chemical Industry.

[Role of p53/p21 signal transduction pathway in the malignant transformation of human embryonic lung fibroblasts induced by quartz].

OBJECTIVE: To observe the expression of p53 protein and investigate the roles of p53 in the expressions and interactions of p21, cyclin D1 and cyclin dependent kinase 4(CDK4) proteins in malignant transformation of human embryonic lung fibroblasts(T-HELF) induced by quartz. METHODS: The cytosolic protein and nuclear protein of both HELF and T-HELF cells were extracted by the separation technique of cytoplasm and nuclei. The distribution and expression of p53, phosphorylated p53 and p21 proteins were detected by Western blot. Based on the RNA interference technique, p53 siRNA was transfected into T-HELF cells to observe the protein expression and change of p53, phosphorylated p53, p21, cyclin D1 and CDK4, while the control group was conducted by transfecting the CMV-neo blank vector into the plasmid. The expression levels of p21, cyclin D1 and CDK4 protein complex in HELF and T-HELF cells were detected by immunoprecipitation. After adding 20 µmol/L of p53 chemical inhibitor pifithrin-α(PFT-α) and 2 µg of p53 siRNA into T-HELF cells respectively, the effect of p53 protein inhibition on p21, cyclin D1 and CDK4 protein complex was also observed. RESULTS: Quartz stimulation of HELF caused a significant increase in the expression of p53 and phosphorylated p53 protein in the nucleus(P<0. 05). The protein expression of p53 in the nucleus of T-HELF was significantly lower than that of HELF(P<0. 05). After transfection of p53 siRNA, the expression of p53 protein was decreased and the expression of p21 and cyclin D1 protein was increased compared with the control group(P<0. 05), while the change of expression in CDK4 was not observed(P>0. 05). Additionally, the result of immunoprecipitation showed that the inhibition of p53 expression could down-regulate the expression level of the binding complex between p21 and cyclin D1 protein(P<0. 05). However, this effect on p21-CDK4 and cyclin D1-CDK4 protein complex was not observed(P>0. 05). CONCLUSION: By regulating the expression and protein-protein interaction between p21 and cyclin D1, p53 would participate in quartz-induced malignant transformation.

[Clinical features of patients with Becker muscular dystrophy and deletions of the rod domain of dystrophin gene].

OBJECTIVE To explore the clinical features of patients carrying deletions of the rod domain of the dystrophin gene. METHODS Clinical data of 12 Chinese patients with Becker muscular dystrophy (BMD) and such deletions was reviewed. RESULTS Most patients complained of muscle weakness of lower limbs. Two patients had muscle cramps, one had increased creatine kinase (CK) level, and one had dilated cardiomyopathy. CONCLUSION Compared with DMD, the clinical features of BMD are much more variable, particularly for those carrying deletions of the rod domain of the dystrophin gene. Muscular weakness may not be the sole complaint of BMD. The diagnosis of BMD cannot be excluded by moderately elevated CK. For male patients with dilated cardiomyopathy, the possibility of BMD should be considered.

Mechanistic insights into sequestration of U(VI) toward magnetic biochar: Batch, XPS and EXAFS techniques.

The magnetic iron oxide (Fe3O4) nanoparticles stabilized on the biochar were synthesized by fast pyrolysis of Fe(II)-loaded hydrophyte biomass under N2 conditions. The batch experiments showed that magnetic biochar presented a large removal capacity (54.35mg/g) at pH3.0 and 293K. The reductive co-precipitation of U(VI) to U(IV) by magnetic biochar was demonstrated according to X-ray diffraction, X-ray photoelectron spectroscopy and X-ray absorption near edge structure analysis. According to extended X-ray absorption fine structure analysis, the occurrence of U-Fe and U-U shells indicated that high effective removal of uranium was primarily inner-sphere coordination and then reductive co-precipitation at low pH. These observations provided the further understanding of uranium removal by magnetic materials in environmental remediation.

Long-term engraftment of myogenic progenitors from adipose-derived stem cells and muscle regeneration in dystrophic mice.

Stem cell therapy is a promising approach for treating Duchenne muscular dystrophy (DMD); however, its application is hindered by poor cell engraftment. There have been no reports to date describing the efficient generation of myogenic progenitors from adipose-derived stem cells (ADSCs) that can contribute to muscle regeneration. In this study, we examined the in vivo myogenic potential of progenitors differentiated from ADSCs using forskolin, basic fibroblast growth factor, the glycogen synthase kinase 3ß inhibitor 6-bromoindirubin-3'-oxime as well as the supernatant of ADSC cultures. The results indicate that a proliferative population of myogenic progenitors can be derived from ADSCs that have characteristics similar to muscle satellite cells and are capable of terminal differentiation into multinucleated myotubes. When transplanted into DMD model mdx mice either by intramuscular injection or systemic delivery, progenitors were successfully engrafted in skeletal muscle for up to 12 weeks, and generated new muscle fibers, restored dystrophin expression and contributed to the satellite cell compartment. These findings highlight the potential application of myogenic progenitors derived from ADSCs to the treatment of muscular dystrophy.

[Analysis of SMN1 gene mutations in 78 patients with spinal muscular atrophy].

OBJECTIVE: To explore the significance of SMN1 gene mutations among patients with spinal muscular atrophy (SMA) and the value of multiplex ligation dependent probe amplification (MLPA) for its diagnosis. METHODS: Potential mutations of the SMN1 gene were detected among 78 SMA patients with a MLPA assay. RESULTS: Homozygous deletion of SMN1 exons 7 and 8 was detected in 70 (89.7%) of all patients. Homozygous deletion of exons 7 and heterozygous deletion of exon 8 was detected in 3 patients (3.8%). Homozygous deletion of SMN1 exons 7 alone was detected in 3 patients (3.8%). Heterozygous deletion of SMN1 exons 7 and 8 was detected in 2 patients (2.6%). For 77 of the patients, both parents were found to carry heterozygous deletion of the SMN1 gene, which was consistent with the recessive inheritance of SMA. One patient with SMA type I was found to be rather rare. The patient was found to carry homozygous deletion of SMN1 exons 7 and 8, for which her mother was heterozygous, while no mutation was found in her father. CONCLUSION: Homozygous deletion of the SMN1 gene have been detected in more than 95% of SMA patients. No homozygous deletion of exon 8 has been found. Homozygous deletion of exon 7 is more significant in the pathogenesis of SMA.

[Anti-atherosclerotic Effects of Bear Bile Powder in Shexiang Tongxin Dripping Pill: a Mechanism Study].

UNLABELLED: OBJECTIVE : To study the anti-atherosclerotic mechanism of bear bile powder (BBP) in Shexiang Tongxin Dripping Pill (STDP) , and to provide scientific evidence for treating atherosclerosis (AS) by its therapeutic characteristics of cool resuscitation. METHODS: AS model was duplicated using ApoE-/- gene knocked mice fed with high-fat diet. Thirty ApoE-/- deficient male mice were divided into four groups according to body weight using random digit table, i.e., the model group (A, n =9), the STDP group (B, n=E7), the STDP without BBP group (C, n =7), and the BBP group (D, n =9). Besides, another 9 C57BL/6J male mice of the same age were recruited as a normal control group (E). All mice in Group B, C, and D were respectively administered with corresponding drugs (30, 30, and 0. 33 mg/kg) by gastrogavage. Equal volume of normal saline was administered to mice in Group A and E. All medication lasted for 8 successive weeks. Serum levels of inflammatory cytokines such as interleukin 2 (IL-2), interleukin 6 (IL-6), tumor necrosis factor a (TNF-α), interferon y (IFNγ), and oxidized low-density lipoprotein (ox-LDL) were measured by ELISA. Serum levels of malondialdehyde (MDA), activities of glutathione (GSH) and superoxide dismutase (SOD) were determined using biochemical assay. Contents of reactive oxygen species (ROS) in the aortic root was detected by dihydroethidum (DHE) fluorescent probe. Expression levels of microRNAs (such as miR-20, miR-21, miR-126, and miR-155) were detected by real-time PCR. RESULTS: The fluorescence intensity of the aorta was obviously enhanced in Group A. But it was obviously attenuated in Group B, C, and D, and the attenuation was the most in Group B. Compared with Group E, serum levels of IL-2, IL-6, TNF-α, IFN-γ, oxLDL, and MDA all increased (P <0. 01), GSH contents and SOD activities decreased (P <0. 01), expression levels of miR-126, miR-21, and miR-155 in aorta increased (P <0. 01), and the expression level of miR-20 decreased in Group A (P<0. 01). Compared with Group A, serum levels of IL-2, IL-6, TNF-α, IFN-γ, oxLDL, and MDA were all down-regulated (P <0. 01), GSH contents and SOD activities were up-regulated (P <0. 01), expression levels of miR-126, miR-21, and miR-155 in aorta were down-regulated in Group B, C, and D (P <0. 01). The expression level of miR20 was up-regulated in Group B and D (P <0. 01). Compared with Group B, serum levels of IL-2, IL-6, TNF-α, IFN-γ increased (P <0.01); GSH contents and SOD activities decreased, levels of MDA and oxLDL increased (P <0. 01) in Group C and D. Expression levels of miR-20 and miR-155 were down-regulated in Group C and D (P <0. 01). CONCLUSIONS: STDP played roles in significantly regulating inflammatory factors and oxidative stress factors. Its mechanism might be possibly associated with regulating expressions of miR-126, miR-21, miR-155, and miR-20 in aorta. BBP played significant roles in STDP.

[Effect of jianpi tongluo jiedu recipe on expression levels of COX-2, NF-kappaBp65, and Bcl-2 in gastric mucosa of patients with precancerous lesions of gastric cancer].

OBJECTIVE: To explore the effect of Jianpi Tongluo Jiedu Recipe (JTJR) on protein expression levels of COX-2, NF-kappaBp65, Bcl-2, and Bax, mRNA expression levels of COX-2 and Bcl-2, and the apoptotic index (Al) in gastric mucosa of patients with precancerous lesions of gastric cancer (PL-GC). METHODS: Totally 65 PLGC patients were recruited and treated by JTJR (modified by syndrome typing), one dose per day for six successive months. Protein expression levels of COX-2, NF-KBp65, Bcl-2, and Bax were detected in 65 patients using immunohistochemical (IHC) assay before and after treatment. mRNA expression levels of COX-2 and Bcl-2 were detected in 54 patients using reverse transcription-polymerase chain reaction (RT-PCR). Meanwhile, changes of Al was detected in 65 patients using TdT-mediated dUTP-biotin nick end labeling (TUNEL) fluorescence method. RESULTS: After treatment with JTJR, positive protein expression levels of COX-2, NF-KBp65, and Bcl-2 were obviously decreased in the gastric mucosa of PLGC patients (P <0.01), but Bax positive protein expression was found to be higher (P < 0.05). At the same time mRNA expression levels of COX-2 and Bcl-2 were significantly lower after treatment than before treatment (P < 0.05, P < 0.01); Al also increased after treatment (P < 0.05). CONCLUSION: JTJR could promote apoptosis possibly via NF-kappaBp65/COX-2, COX-2/Bcl-2, and NF-kappaBp65/Bcl-2 signaling pathways, thereby affecting PLGC patients.

Investigation on the mechanisms for biotransformation of saponins to diosgenin.

In order to improve the efficiency of biotransformation of saponins in Dioscorea zingiberensis to diosgenin, a new enzymatic model was developed to investigate the mechanism of the metabolic systems. Four main saponin hydrolases (E1, E2, E3 and E4) were purified from Trichoderma reesei. Using progracillin as substrate, the enzymatic hydrolysis experiments with E1, E2, E3 and E4 were carried out respectively. Saponin concentrations during each biotransformation reaction were constructed with a kinetic model consisting of a few Michaelis-Menten equations. During biotransformation, C-26 glycoside and C-3 terminal glycoside were cleaved sequentially from saponins by E1, E2, E3 and E4. Then C-3 terminal rhamnoside and C-3 glycoside were released from the aglycone stepwisely by E2 and E3, to yield diosgenin. E2 and E3 were the key enzymes in the system, and cleavage of the C-3 glycoside from saponins was the rate-limiting step in the biotransformation process. The proposed enzymatic model might be used to analyze the mechanism for biotransformation of saponins to diosgenin.

Evaluation of different pretreatments on microbial transformation of saponins in Dioscorea zingiberensis for diosgenin production.

In order to evaluate the effects of different pretreatments on microbial transformation of saponins in Dioscorea zingiberensis (DZW), various methods have been systematically studied on a large scale. Five pretreatments, including physical separation, catalytic solvent extraction, ultrasonic fermentation, complex enzymatic hydrolyzation and enzymatic saccharification, were performed on DZW. Compared with other methods, complex enzymatic hydrolyzation significantly improved the efficiency of microbial transformation. Due to the pretreatment, a diosgenin yield of 92.6%, and diosgenin accumulation of 27.3 mg/g DZW were achieved. The high efficiency of this method was attributed to the separation of 84.3% starch and 76.5% fibre from DZW in the form of a sugar. Analysis of saponins in this microbial transformation process showed that the residual rates of the intermediate products were much lower than those obtained from other pretreatments. The results demonstrate that complex enzymatic hydrolyzation is a practical and effective pretreatment method for production of diosgenin from DZW in a microbial transformation way.

[Determination of 2, 4-dichlorophenoxyacetic acid in air of workplace by high-performance liquid chromatography].

OBJECTIVE: To develop a method for determination of 2, 4-dichlorophenoxyacetic acid (2, 4-D) in the air of workplace by high-performance liquid chromatography. METHODS: 2, 4-D was collected by ultrafine glass filters, desorbed by methanol, separated by a C18 column, and detected by a UV detector. Identification and quantification of 2, 4-D were performed by retention time and peak areas, respectively. RESULTS: The linear range of the test was 2∼200 µg/ml; the elution efficiency was 94.6%- 95.9%; the limit of detection (S/N = 3) was 0.034 µg/ml (injection volume of 20 µl eluant); the lower limit of quantification (S/N = 10) was 0.11 µg/ml; the minimum detectable concentration was 0.011 mg/m(3); the minimum quantifiable concentration was 0.037 mg/m(3) (with sampled air volume of 45 L). CONCLUSION: This method is convenient and simple in sample collection and preparation, and satisfies all methodological requirements. Therefore, this method is useful for the determination of 2, 4-D in the air of workplace.

Efficacy of predictive pain intervention in patients with aortic dissection.

BACKGROUND: Aortic dissection is usually managed with interventional therapy, conservative therapy, and surgery to inhibit disease progression and improve prognoses. Nevertheless, the absence of meticulous and effective nursing during the treatment greatly increases the complication rates, which is detrimental to the recovery of patients. OBJECTIVE: This study aimed to explore the efficacy of predictive pain intervention in the nursing process of patients with aortic dissection. METHODS: Sixty patients with aortic dissection who were admitted to our hospital from December 2018 to December 2020 were observed in this study. Specifically, these patients were randomly and equally classified into Group A (patients who were given conventional nursing intervention) and Group B (patients who were given predictive pain intervention). Subsequently, the pain score, complication rates, and nursing satisfaction in the two groups were compared and analyzed. RESULTS: Compared with patients in Group A, patients in Group B had significantly lower pain scores (P< 0.05); complication rates were significantly lower in Group B than in Group A (6.67% vs. 23.33%, P< 0.05); patient satisfaction with care was significantly better in Group B compared to Group A (96.67% vs. 73.33%, P< 0.05). CONCLUSION: Predictive pain intervention is widely recognized as useful in the treatment of patients with aortic dissection. It has significant clinical application value as it can largely alleviate pain and is relatively safe for patients.

Suicide attempt and suicidal ideation and their associations with demographic and clinical correlates and quality of life in Chinese schizophrenia patients.

OBJECTIVES: This study aimed to examine the prevalence and correlates of lifetime suicide attempts and current suicidal ideation in community-dwelling schizophrenia patients in China. METHOD: A sample of 540 schizophrenia patients was randomly selected in Beijing, China. All subjects were interviewed using standardized assessment instruments and their basic socio-demographic and clinical data including history of suicide attempts were collected. RESULTS: The prevalence of lifetime suicide attempts and the point prevalence of suicidal ideation were 12.0%, and 21.1%, respectively. In multiple logistic regression analyses, the presence of lifetime suicide attempt was independently associated with rural residence, having major medical conditions and better social functioning, while higher likelihood of current suicidal ideation was associated with past suicide attempt, the severity of overall psychopathology and depressive symptoms and lower psychological quality of life (QOL). CONCLUSION: Among Chinese outpatients with schizophrenia, increased current symptoms and poorer QOL were correlated with current suicidal ideation, while demographic factors and indicators of greater social support were mostly correlated with lifetime suicide attempts. This study may help to identify important subgroups of patients with schizophrenia at particularly high risk of suicidal behavior.