Tag: statistics

Huan Jing Ke Xue. 2023 Mar 8;44(3):1553-1561. doi: 10.13227/j.hjkx.202203270.

ABSTRACT

Farmland is the important soil carbon pool of terrestrial ecosystems and organic nutrient pool for crop growth. To clarify the impact of climate warming on the soil carbon pool, this study analyzed the effects of warming and fertilization on soil organic carbon and its labile components under rice-wheat rotation using a free-air temperature increase system. The variation in soil carbon pool management index (CPMI) was also evaluated. The results showed that the combined effects of warming and fertilization on soil organic carbon content and labile organic carbon components were insignificant. Warming increased the soil organic carbon (SOC) content, and the differences between warming and the ambient control in total organic carbon (TOC) and recalcitrant organic carbon (ROC) reached a statistically significant level. Compared with those under the ambient control, the contents of TOC, ROC, and labile organic carbon (LOC) subjected to warming increased by 7.72%, 7.42%, and 10.11%, respectively. The increased microbial biomass carbon (MBC) content (20.4%) and decreased particulate organic carbon (POC) content (36.51%) may have been the main reason for the variation in SOC. Warming showed no significant effect on soil dissolved organic carbon (DOC) content, whereas it markedly reduced its soluble microbial by-product components (41.89%). The results also showed that fertilization had no significant effect on soil TOC, ROC, and LOC, but it notably reduced the contents of DOC and POC and increased the MBC content. Compared with those under the control without fertilization, the contents of DOC and POC subjected to fertilization decreased by 35.44% and 28.33%, respectively, and the MBC content increased by 33.38%. Additionally, fertilization tended to increase the anthropogenic humus component (5.13%) and soluble microbial by-product component (29.41%) in dissolved organic matter and reduce the terrestrial humus component (13.33%). Warming and fertilization both tended to improve soil CPMI. Affected by SOC and LOC, the increase in soil carbon pool index and soil lability index were the main reason for the increase in soil CPMI under warming and fertilization, respectively. Overall, the results revealed that climate warming can affect the soil carbon pool by changing soil labile carbon components, which are not affected by fertilization.

PMID:36922216 | DOI:10.13227/j.hjkx.202203270

Zhonghua Yu Fang Yi Xue Za Zhi. 2023 Mar 6;57(3):427-432. doi: 10.3760/cma.j.cn112150-20221016-00998.

ABSTRACT

To observe the symptom control, pulmonary function changes and safety of use of omalizumab in patients with moderate to severe allergic asthma for 1 year. A small sample self-controlled study before and after treatment was conducted to retrospective analysis involved 17 patients with moderate to severe asthma who received omalizumab therapy for 12 months in Peking University People’s Hospital and Beijing Jishuitan Hospital from January 2020 to December 2021. The clinical symptoms and pulmonary function changes were compared before treatment, after 6 months and 12 months of treatment, and the clinical data such as the use of other drugs and adverse reactions were observed. Statistical data are collected using the median method, and non-parametric paired Wilcoxon analysis was used for pairwise comparison. Before treatment with omalizumab, the patients’ FeNO value was 79(58, 121) ppb, and the total serum IgE was 228(150.5, 345.5) IU/ml. After 6 months of omalizumab therapy, the percent predicted value of the forced expiratory volume in 1 second (FEV1%) before inhaled bronchodilator increased from 86.70(82.65, 91.35)% to 90.90(87.70, 95.85)% (Z=-3.626, P<0.001). The FEV1%pred after inhaled bronchodilator increased from 92.60(85.75, 96.90)% to 94.30(89.95, 98.15)% (Z=-2.178, P=0.029). The absolute value of improvement in FEV1 decreased from 150(95, 210)ml to 50(20, 125) ml (Z=-2.796, P=0.005), and the improvement rate decreased from 6.60(3.80, 7.85)% to 1.90(0.75, 4.85)% (Z=-2.922, P=0.003). After 12 months of treatment, the FEV1%pred before inhaled bronchodilator further increased to 92.90 (91.60, 98.15)% (Z=-3.575, -2.818, and P<0.001, 0.005 compared with before treatment and 6 months after treatment, respectively). The FEV1%pred after inhaled bronchodilator increased to 96.80 (91.90, 101.25)% (Z=-3.622, -1.638, and P<0.001, 0.008 compared with before treatment and after 6 months of treatment, respectively). The absolute value of improvement in FEV1 was 70 (35, 120) ml (P=0.004, 0.842 before treatment and 6 months after treatment, respectively), and the improvement rate was 3.0(1.0, 5.0)% (Z=-2.960, -0.166, and P=0.003, 0.868, compared with before treatment and after 6 months of treatment, respectively). After 12 months of treatment, ACT increased from 13 (10.5, 18) before treatment to 24 (23, 25) (Z=-3.626,P<0.001). Only 1 patient experienced an injection site skin reaction during treatment. Therefore, after 6 months and 12 months of treatment with omalizumab, the patient’s lung function improved and symptoms were relieved, which could effectively prevent the acute exacerbation of asthma. Omalizumab treatment is safe and well tolerated, and no effect on blood pressure and blood glucose was observed.

PMID:36922178 | DOI:10.3760/cma.j.cn112150-20221016-00998

Zhonghua Yu Fang Yi Xue Za Zhi. 2023 Mar 6;57(3):416-421. doi: 10.3760/cma.j.cn112150-20221118-01121.

ABSTRACT

To explore the clinical distribution and drug resistance characteristics of carbapenem-resistant Klebsiella pneumoniae (CRKP), in order to provide reference for the prevention and treatment of CRKP infection. Retrospective analysis was performed on 510 clinical isolates of CRKP from January 2017 to December 2021, and strain identification and drug sensitivity tests were conducted by MALDI-TOF mass spectrometer and VITEK-2 Compact microbial drug sensitivity analyzer. The carbapenemase phenotype of CRKP strain was detected by carbapenemase inhibitor enhancement test. The CRKP strain was further categorized by immunochromogenic method and polymerase chain reaction (PCR) was used for gene detection. The results showed that 302 strains (59.2%) were derived from sputum, 127 strains (24.9%) from urine and 47 strains (9.2%) from blood. 231 (45.3%) were mainly distributed in intensive care, followed by 108 (21.2%) in respiratory medicine and 79 (15.5%) in neurosurgery. Drug susceptibility test result shows that the resistant rate of tigecycline increased from 1.0% in 2017 to 10.1% in 2021, the difference was statistically significant (χ²=14.444,P<0.05). The results of carbapenemase inhibitor enhancement test showed that 461 carbapenemase strains (90.4%) of 510 CRKP strains, including 450 serinase strains (88.2%), 9 metalloenzyme strains (1.8%), and 2 strains (0.4%) produced both serine and metalloenzyme. 49 strains (9.6%) did not produce enzymes. Further typing by immunochromogenic assay showed that 461 CRKP strains were KPC 450 (97.6%) and IMP 2 (0.4%). 7 NDM (1.5%); 2 strains of KPC+NDM (0.4%); PCR results were as follows: 450 strains of blaKPC (97.6%), 2 strains of blaIMP (0.4%), 7 strains of blaNDM (1.5%), and 2 strains of blaKPC+NDM (0.4%). In conclusion, CRKP strains mainly originated from sputum specimens and distributed in intensive care department, and the drug resistance characteristics were mainly KPC type in carbapenemase production. Clinical microbiology laboratory should strengthen the monitoring of CRKP strains, so as to provide reference for preventing CRKP infection and reducing the production of bacterial drug resistance.

PMID:36922176 | DOI:10.3760/cma.j.cn112150-20221118-01121

Zhonghua Yu Fang Yi Xue Za Zhi. 2023 Mar 6;57(3):393-399. doi: 10.3760/cma.j.cn112150-20221110-01090.

ABSTRACT

Objective: To analyze the characteristics of human papillomavirus (HPV) infection and the distribution of HPV subtypes in Shijiazhuang, Hebei Province, and to explore the application evaluation of multiple PCR capillary electrophoresis fragment analysis for HPV typing test. Methods: A population-based cross-sectional study was conducted among 434 women (age range 17 to 74 years old, 260 patients and 174 physical examinations) included from May to August 2022 in Hebei General Hospital. HPV typing was detected by multiple PCR-capillary electrophoresis fragment analysis. Using the multiple fluorescence quantitative PCR kit as a reference, Chi-square test was used to analyze the diagnostic effect of multiple PCR-capillary electrophoresis fragment analysis, and the consistency was analyzed by Kappa value. Results: The total HPV infection rate was 45.85%(199/434), including 35.48% (154/434) of high-risk HPV (HR-HPV), 3.92% (17/434) of low-risk HPV (LR-HPV), 6.45% (28/434) of HR-HPV and LR-HPV mixed infection, 27.88% (121/434) of single type HPV and 17.97% (78/434) of multi type HPV. HPV52 (9.68%, 42/434), HPV16 (6.91%, 30/434), and HPV58 (6.91%, 30/434) are common HPV subtypes. The positive rate of physical examination was 45.40% (79/174), which was slightly lower than that of patients 46.15% (120/260), there was no significant difference (χ²=0.024,P>0.05). The highest infection rate in the 17-30 age group was 54.76% (46/84), and there was no statistical difference among the age groups(χ²=4.123,P>0.05). The sensitivity and specificity of multiplex PCR capillary electrophoresis fragment analysis were 92.96% and 94.04%, respectively, and Kappa value was 0.870, with the multiplex fluorescent quantitative PCR as the reference. Conclusion: HPV infection may appear younger, and the positive rate of HR-HPV infection is the highest, with HPV52, 16, 58 as the main infection subtypes. The detection results of multiplex PCR capillary electrophoresis fragment analysis method are highly consistent with those of multiplex fluorescent quantitative PCR method, which is suitable for HPV DNA typing.

PMID:36922173 | DOI:10.3760/cma.j.cn112150-20221110-01090

J Chem Phys. 2023 Mar 14;158(10):104906. doi: 10.1063/5.0133489.

ABSTRACT

Polymers consisting of more than one type of monomer, known as copolymers, are vital to both living and synthetic systems. Copolymerization has been studied theoretically in a number of contexts, often by considering a Markov process in which monomers are added or removed from the growing tip of a long copolymer. To date, the analysis of the most general models of this class has necessitated simulation. We present a general method for analyzing such processes without resorting to simulation. Our method can be applied to models with an arbitrary network of sub-steps prior to addition or removal of a monomer, including non-equilibrium kinetic proofreading cycles. Moreover, the approach allows for a dependency of addition and removal reactions on the neighboring site in the copolymer and thermodynamically self-consistent models in which all steps are assumed to be microscopically reversible. Using our approach, thermodynamic quantities such as chemical work; kinetic quantities such as time taken to grow; and statistical quantities such as the distribution of monomer types in the growing copolymer can be directly derived either analytically or numerically from the model definition.

PMID:36922142 | DOI:10.1063/5.0133489

JACC Cardiovasc Interv. 2023 Mar 13;16(5):530-539. doi: 10.1016/j.jcin.2022.12.019.

ABSTRACT

BACKGROUND: Valve-in-valve (VIV) transcatheter aortic valve replacement (TAVR) is increasingly used to treat degenerated surgical bioprostheses. Bioprosthetic valve fracture (BVF) has been shown to improve hemodynamic status in VIV TAVR in case series. However, the safety and efficacy of BVF are unknown.

OBJECTIVES: The primary objective of this study was to assess the safety and efficacy of VIV TAVR using SAPIEN 3 and SAPIEN 3 Ultra valves with or without BVF using data from the Society of Thoracic Surgeons/American College of Cardiology TVT (Transcatheter Valve Therapy) Registry.

METHODS: The primary outcome was in-hospital mortality. Secondary outcomes included echocardiography-derived valve gradient and aortic valve area. Inverse probability of treatment weighting was used to adjust for baseline characteristics.

RESULTS: A total of 2,975 patients underwent VIV TAVR from December 15, 2020, to March 31, 2022. BVF was attempted in 619 patients (21%). In adjusted analyses, attempted BVF was associated with higher in-hospital mortality (OR: 2.51; 95% CI: 1.30-4.84) and life-threatening bleeding (OR: 2.55; 95% CI: 1.44-4.50). At discharge, VIV TAVR with attempted BVF was associated with larger aortic valve area (1.6 cm² vs 1.4 cm²; P < 0.01) and lower mean gradient (16.3 mm Hg vs 19.2 mm Hg; P < 0.01). When BVF was compared with no BVF according to timing (before vs after transcatheter heart valve implantation), BVF after transcatheter heart valve implantation was associated with improved hemodynamic status and similar mortality.

CONCLUSIONS: BVF as an adjunct to VIV TAVR with the SAPIEN 3 and SAPIEN 3 Ultra valves is associated with a higher risk for in-hospital mortality and significant bleeding and modest improvements in echocardiography-derived hemodynamic status. The timing of BVF is an important determinant of safety and efficacy.

PMID:36922038 | DOI:10.1016/j.jcin.2022.12.019

J Neurointerv Surg. 2023 Mar 15:jnis-2023-020094. doi: 10.1136/jnis-2023-020094. Online ahead of print.

ABSTRACT

BACKGROUND: Cangrelor is an intravenous P2Y12 inhibitor with rapid onset and fast offset of antiplatelet action. Dose adjusted cangrelor based on platelet function testing is suggested to be advantageous for use during neuroendovascular procedures. In this study, we aimed to assess the efficacy and safety of this strategy.

METHODS: This retrospective study included consecutive patients who received low dose intravenous cangrelor (5 µg/kg; infusion 1 µg/kg/min) for ruptured (RIA) and unruptured (UIA) intracranial aneurysms, and acute ischemic stroke (AIS). Indications were acute stenting or intraluminal thrombus. Outcomes were assessed at 24 hours by brain CT and CT angiography. The primary efficacy outcome was the rate of stent occlusion or persistent intraluminal thrombus. The primary safety outcome was the rate of major hemorrhages.

RESULTS: 101 patients (56 men; median age (IQR) 59 (51-70) years) received low dose cangrelor for acute stenting (79/101 (78%)) and intraprocedural thrombus (22/101 (22%)). Overall, 5 (4.9%) patients experienced stent occlusion within 24 hours (RIA 3/28; AIS 2/52). There were no cases of failure among UIA patients. Stent mis-opening (fish mouthing or stenosis >50%) was significantly associated with stent occlusion (P<0.001). The overall rate of major hemorrhage was 2% (2/101), which occurred in AIS patients. Platelet reactivity unit (PRU) values were lower in those presenting with major hemorrhage (PRU 4 (SD 1.4) vs PRU 60 (SD 63); P=0.043). Mortality rate after cangrelor related hemorrhage was 1%.

CONCLUSIONS: Low dose cangrelor appears to be effective in preventing stent thrombosis and arterial patency with a low hemorrhagic risk.

PMID:36922032 | DOI:10.1136/jnis-2023-020094

Br J Haematol. 2023 Mar 15. doi: 10.1111/bjh.18734. Online ahead of print.

ABSTRACT

The Children’s Oncology Group AHOD0831 study used a positron emission tomography (PET) response-adapted approach in high-risk Hodgkin lymphoma, whereby slow early responders (SERs) received more intensive therapy than rapid early responders (RERs). We explored if baseline PET-based characteristics would improve risk stratification. Of 166 patients enrolled in the COG AHOD0831 study, 94 (57%) had baseline PET scans evaluable for quantitative analysis. For these patients, total body metabolic tumour volume (MTV), total lesion glycolysis (TLG), maximum standardized uptake value (SUV_max ) and peak SUV (SUV_peak ) were obtained. MTV/TLG thresholds were an SUV of 2.5 (MTV_2.5 /TLG_2.5 ) and 40% of the tumour SUV_max (MTV_40% /TLG_40% ). TLG_2.5 was associated with event-free survival (EFS) in the complete cohort (p = 0.04) and in RERs (p = 0.01), but not in SERs (p = 0.8). The Youden index cut-off for TLG_2.5 was 1841. Four-year EFS was 92% for RER/TLG_2.5 up to 1841, 60% for RER/TLG_2.5 greater than 1841, 74% for SER/TLG_2.5 up to 1841 and 79% for SER/TLG_2.5 greater than 1841. Second EFS for RER/TLG_2.5 up to 1841 was 100%. Thus, RERs with a low baseline TLG_2.5 experienced excellent EFS with less intensive therapy, whereas RERs with a high baseline TLG_2.5 experienced poor EFS. These findings suggest that patients with a high upfront tumour burden may benefit from intensified therapy, even if they achieve a RER.

PMID:36922022 | DOI:10.1111/bjh.18734

Otol Neurotol. 2023 Mar 14. doi: 10.1097/MAO.0000000000003847. Online ahead of print.

ABSTRACT

OBJECTIVE: Many but not all patients with idiopathic intracranial hypertension (IIH) have pulsatile tinnitus (PT). However, little is known about why some patients with IIH develop PT and others do not. The purpose of this study was to determine if any of the classic magnetic resonance imaging (MRI)-detectable markers of IIH differ between patients with and without PT, thereby shedding light on potential pathophysiology.

METHODS: A retrospective age-matched cohort study of patients with documented IIH (diagnosed by neuro-ophthalmologist) was performed. All patients had MRI performed around the time of diagnosis. MRIs were assessed for 16 variables known to be associated with IIH (e.g., pituitary displacement/empty sella, optic nerve tortuosity, transverse sinus stenosis, inferior cerebellar tonsils, arachnoid granulations, slit-like ventricles) by two blinded neuroradiologists. All binary variables were analyzed via χ2 test with Yates correction, or Fisher exact when appropriate. Continuous variables were analyzed via Student t test. Inter-rater reliability for binary variables was assessed by Cohen κ. For continuous variables, intraclass correlation coefficient was calculated.

RESULTS: Forty age-matched patients with IIH met the inclusion criteria (20 with PT, 20 without PT). For all known binary MRI findings associated with IIH, there were no statistically significant differences between groups. Likewise, there were no statistically significant differences for continuous variables.

CONCLUSIONS: The classic MRI findings associated with IIH do not differ between patients with and without PT, suggesting that systemic (rather than localized intrinsic or extrinsic) factors may play a critical role in the pathophysiology.

PMID:36922020 | DOI:10.1097/MAO.0000000000003847

Genome Res. 2023 Mar 15:gr.276992.122. doi: 10.1101/gr.276992.122. Online ahead of print.

ABSTRACT

While mutation rates have been extensively studied, variation in mutation rates throughout the genome is poorly understood. To understand patterns of genetic variation, it is important to understand how mutation rates vary. Chromatin modifications may be an important factor in determining variation in mutation rates in eukaryotic genomes. To study variation in mutation rates, we performed a mutation accumulation experiment in the filamentous fungus Neurospora crassa, and sequenced the genomes of the 40 MA lines that had been propagated asexually for approximately 1015 [1003, 1026] mitoses. We detected 1322 mutations in total, and observed that the mutation rate was higher in regions of low GC, in domains of H3K9 trimethylation, in centromeric regions, and in domains of H3K27 trimethylation. The rate of single nucleotide mutations in euchromatin was 2.46 [2.19, 2.77] × 10^-10 In contrast, the mutation rate in H3K9me3 domains was tenfold higher: 2.43 [2.25, 2.62] × 10^-9 We also observed that the spectrum of single nucleotide mutations was different between H3K9me3 and euchromatic domains. Our statistical model of mutation rate variation predicted a moderate amount of extant genetic variation, suggesting that the mutation rate is an important factor in determining levels of natural genetic variation. Furthermore, we characterized mutation rates of structural variants, complex mutations, and the effect of local sequence context on the mutation rate. Our study highlights that chromatin modifications are associated with mutation rates, and accurate evolutionary inferences should take variation in mutation rates across the genome into account.

PMID:36922001 | DOI:10.1101/gr.276992.122