Category: Nevin Manimala

Dent Mater. 2023 Mar 13:S0109-5641(23)00063-5. doi: 10.1016/j.dental.2023.03.003. Online ahead of print.

ABSTRACT

OBJECTIVE: The objective of this study was to assess the influence of immediate dentin sealing (IDS) on the fatigue behavior of laminate occlusal veneers fabricated with CAD/CAM lithium disilicate ceramic and resin composite.

METHODS: Forty sound human molars were prepared and randomly divided into 4 groups (n = 10): RC-IDS+ (IDS and resin composite occlusal laminate veneer); RC-IDS- (resin composite occlusal laminate veneer without IDS); LD-IDS+ (IDS and lithium disilicate laminate veneer); LD-IDS- (lithium disilicate occlusal laminate veneer without IDS). The restorations were obtained using a digital workflow. After surface conditioning and bonding, thermocycling and accelerated fatigue tests (20 Hz, 5000 cycles with an initial load of 300 N, step-size of 100 N for 10,000 cycles, up to 1000 N, and then a step-size of 50 N until failure) were conducted. Fatigue data were recorded for both outcomes (crack or fracture) and statistically analyzed. Fractographic and adhesive interface analysis were conducted.

RESULTS: The indirect resin composite groups showed better fatigue behavior compared to lithium disilicate. IDS only had a positive effect for the survival of resin composite restorations for the ‘fracture’ outcome. Evident presence of micro-gaps at the adhesive interface in the LD-IDS- group could be noted.

SIGNIFICANCE: Immediate dentin sealing improved fatigue resistance behavior of resin composite occlusal veneers. However, this effect was not observed in lithium disilicate veneers.

PMID:36922258 | DOI:10.1016/j.dental.2023.03.003

Huan Jing Ke Xue. 2023 Mar 8;44(3):1686-1697. doi: 10.13227/j.hjkx.202203292.

ABSTRACT

In order to explore the pollution characteristics and health risks of heavy metals in a soil-crop system in the Anhui section of the Yangtze River basin, a total of 338 groups of soil samples from rice, wheat, and their roots were collected, and the contents of eight types of heavy metals were determined. Additionally, the pollution index method, potential ecological hazard, multivariate statistical analysis, and health risk were used to evaluate the heavy metal content in rice and wheat root soil. The results showed that Cd, Cu, Cr, and Ni in the soil had an obvious accumulation effect, and the pollution of rice root soil was more serious than that of wheat soil. The potential ecological risk was mild to moderate, which mainly came from the elements Cd and Hg. Multivariate statistical analysis showed that Cu, Pb, Zn, and Cd were industrial sources and agricultural sources; Cr and Ni were natural sources; and As and Hg were agricultural sources. The absorption and enrichment intensity of heavy metals by rice was in the order of Cd>Zn>Cu>Hg>Ni>As>Cr=Pb, and those in wheat were ordered as Zn>Cd>Cu>Hg>Ni>As=Pb>Cr. The root soil heavy metal health risk assessment indicated that oral intake was the main exposure route of non-carcinogenic risk, and children were more vulnerable to heavy metal pollution. Non-carcinogenic risk assessment showed that wheat root soil posed non-carcinogenic risk to children but no carcinogenic risk. Intake of rice and wheat had some degree of non-carcinogenic risk and unacceptable carcinogenic risk for both adults and children.

PMID:36922229 | DOI:10.13227/j.hjkx.202203292

Huan Jing Ke Xue. 2023 Mar 8;44(3):1657-1667. doi: 10.13227/j.hjkx.202201279.

ABSTRACT

Heavy metal pollution in testing ranges is one of the most widely concerning environmental problems. The ammunition static detonation test area, the bomb falling area, and the living area of a testing range in Jilin were selected as the study objects. The contents of heavy metals (As, Cd, Cr, Cu, Ni, Pb, and Zn) in 112 topsoil samples and two soil profiles were analyzed, and their distribution characteristics and sources were analyzed in detail. After that, the pollution degree and potential ecological risk of heavy metals were investigated using multiple pollution index assessment methods. The results showed that the average contents of As, Cd, Cu, Ni, and Zn in the soil of the ammunition static detonation test area were higher than the soil background values in Jilin province, and the contents of Cu, Zn, As, and Cd showed strong spatial heterogeneity. The average concentrations of As, Cd, and Ni in the soil of the bomb falling area exceeded their background values. The average contents of As and Cd in the soil of the living area were higher than the background values, and the variation coefficients of Pb, Cd, Zn, and Cr were relatively high, indicating that they may have been affected by human activities. In different test areas, the contents of As, Cr, Cu, Ni, and Zn in the soil samples were significantly different (P<0.05). The ammunition static detonation test area was more strongly affected by the test activities than the bomb falling area, and the heavy metal contents in the surface layer of the soil profile were significantly higher. There was no obvious vertical migration of heavy metals in the soil profiles. The results of multivariate statistics and source identification analysis using absolute principal component score-multiple linear regression (APCS-MLR) showed that Zn, Pb, and Cd were mainly affected by pollution sources related to test activities; Cr and Ni were mainly affected by natural sources of soil forming materials; and the sources of As and Cu were more complicated. The geo-accumulation index showed that Cd in the three areas and Ni in the bomb falling area belonged to pollution level 1 (uncontaminated to moderately contaminated). The Nemerow comprehensive pollution index showed that the pollution levels among the different functional areas were:living area>ammunition static detonation test area>bomb falling area, and the three functional areas were slightly polluted. The potential ecological risk index showed that the study area was at moderate ecological risk level, and Cd was considered to be the main soil pollution factor.

PMID:36922226 | DOI:10.13227/j.hjkx.202201279

Huan Jing Ke Xue. 2023 Mar 8;44(3):1620-1635. doi: 10.13227/j.hjkx.202204096.

ABSTRACT

In this study, As, Cd, Cr, Hg, and Pb in the surface soil of cropland in Lanzhou were studied, and the combination of descriptive statistics, single-factor accumulation index, comprehensive accumulation index, geostatistical method, and a geographically weighted regression model (GWR) was used to investigate their accumulation status, spatial distribution, and influencing factors, in order to provide scientific basis for the precise control of heavy metal accumulation risk in the study area. The results showed that:①the single-factor accumulation index showed that the accumulation of Hg and Cd in the study area was the largest, followed by that of Pb and As, and that of Cr was the smallest; the comprehensive accumulation index showed that the accumulation rate of heavy metals was as high as 98.11%, of which 54.81% was mild accumulation and 43.30% was moderate and above accumulation. However, there was no heavy metal pollution in the surface soil of cultivated land in Lanzhou. ② Spatial autocorrelation analysis showed that there was no heavy metal pollution in the surface soil of Lanzhou, but there was accumulation in a few areas. The spatial autocorrelation analysis showed that the spatial autocorrelation of the Cr, Hg, and Pb single-factor accumulation indices was moderate, indicating that they were influenced by both random and structural factors; the spatial autocorrelation of the other two heavy metals was weak, indicating that they were mainly influenced by random factors, among which human factors were more influential. The Hg single-factor accumulation index was high in the middle and low in the fourth; the integrated accumulation index increased from northwest to southeast and decreased from the middle to both sides. ③ Geographically weighted regression (GWR) analysis showed that altitude, slope length, distance from rivers, soil organic matter (SOM) content, precipitation, air temperature, and surface temperature all showed positive driving effects, whereas the rest of the factors showed negative driving effects and significant spatial heterogeneity and instability (P<0.05). The magnitudes of the factor effects were in the order of soil characteristics>topographic characteristics>climate characteristics>location characteristics>socioeconomic characteristics>vegetation characteristics, with the largest contribution of SOM content, followed by that of altitude and air temperature, and the smallest of normalized difference vegetation index (NDVI) values. Compared with the other feature factors, the location feature factors had stronger spatial heterogeneity.

PMID:36922223 | DOI:10.13227/j.hjkx.202204096

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