Tag: statistics

Se Pu. 2021 Apr 8;39(4):376-383. doi: 10.3724/SP.J.1123.2020.09015.

ABSTRACT

The ratio of stable isotopes of the elements in explosives differs depending on the raw materials obtained from different geographical sources or the production processes adopted. Hence, this ratio can be used as an important index for the comparison and trace of explosives. Isotope ratio mass spectrometry (IRMS), a high-precision method for the analysis of stable isotope ratios, has evolved into a mature tool in this regard. In combination with elemental analysis, gas chromatography, liquid chromatography, etc., IRMS is widely used in food safety, environmental protection, forensic science, and other fields. IRMS also plays an important role in the comparison and trace of explosives. Since its application to distinguish trinitrotoluene (TNT) produced in different countries in 1975, IRMS has been successfully used in the analysis of various explosives. However, there is no systematic summary on the research progress on the stable isotope ratio analysis of common explosives. This paper provides a brief description of the related principle, instrumental composition, and characteristics of stable isotope ratio analysis. Methods for the stable isotope ratio analysis of common explosives such as ammonium nitrate, black powder, TNT, pentaerythritol tetranitrate (PETN), and cyclotrimethylene trinitroamine (RDX) are reviewed. The bulk stable isotopic ratio analysis method was used in most of the studies to determine the total isotope ratio of the sample. A compound-specific isotope analysis method was also employed to determine the isotope ratio of organic explosives in a complex matrix. The reported stable isotope ratios of explosives such as ammonium nitrate, black powder, and TNT produced in different countries are summarized. The discrimination ability of the stable isotope ratio for explosives is discussed. Based on the stable isotope ratio, explosives from different sources can be distinguished effectively. By combining the results of elemental analysis with the ICP-MS results, the discrimination efficiency of different samples could be further improved. The influence of relevant factors on the isotope ratio during the production and storage of explosives are collated. There is a strong correlation between the stable isotope ratios of explosives and raw materials. The stable isotope ratios of TNT, PETN, and other explosives are related to that of nitric acid used in the production. The stable isotope ratios of nitrogen and oxygen in the explosive are relatively stable and almost unchanged within one year of production. The complexity of the environmental matrix at the explosion site and the low concentration of explosive residues make the stable isotope analysis of explosive residues challenging. However, the changes in the stable isotope ratio before and after the explosion are discussed. Since there is no information on the application of stable isotope analysis to the traceability of explosives, the paper mentions that the standardized explosive sample pretreatment, stable isotope analysis method, collection and analysis of large amounts of explosive samples, and explosive stable isotope database are the basis of explosive traceability. This paper also outlines the existing challenges in the analysis of the stable isotope ratios of explosives, including the small number of explosive samples, lack of a stable isotope explosive analysis database, and difficulty in the stable isotope analysis of explosive residues. Possible solutions to these problems are proposed, followed by suggestions for the future development of the stable isotope ratio analysis of common explosives. The suggestions include establishing an effective extraction and enrichment method for explosive residues, combining IRMS with GC or LC for analyzing explosives, establishing a comprehensive process for the analysis of the stable isotope ratios of inorganic and organic explosives, and comparison and analysis of the stable isotope analysis data using statistical methods.

PMID:34227757 | DOI:10.3724/SP.J.1123.2020.09015

Kardiol Pol. 2021 Jul 6. doi: 10.33963/KP.a2021.0054. Online ahead of print.

ABSTRACT

Low values on heart rate variability (HRV) derived parameters at resting have been used to predict cardiovascular diseases (CVD) and mortality. In this regard, short-term HRV recordings (usually from 5-min to 15-min) are increasing their popularity because data acquisition can be performed under more controlled conditions than long-term recordings (e.g., 24-h). However, different methodological aspects before, during, and after the HRV assessment could affect the quantification and the clinical interpretations of the HRV derived parameters, as well as hampers comparisons across different studies. Here, we summarize these methodological aspects that should be considered in both the research and the clinical settings. These are: 1) the validity and reproducibility of the device used to assess the HRV; 2) the influence of the software used to perform the artefact correction; 3) previous conditions before the testing day; 4) establish the proper conditions during the HRV assessment (e.g., controlled respiratory frequency); 5) after assessing the HRV, consider the “best” data selection and statistical analyses approach; and, 6) the role of the heart rate on the associations between the different CVD risk factors outcomes (e.g., cardiorespiratory fitness) and the HRV derived parameters.

PMID:34227676 | DOI:10.33963/KP.a2021.0054

Epilepsia. 2021 Jul 6. doi: 10.1111/epi.16981. Online ahead of print.

ABSTRACT

We aimed to explore brain area(s) involved in the generation of ictal asystole (IA) by analyzing the interictal positron emission tomography (PET) metabolism of patients with IA recorded by video-electroencephalography or video-stereo-electroencephalography. We identified in our cohort of focal epilepsy patients who had undergone presurgical evaluation those who had a recorded period of IA of more than 3 s. We investigated the anatomometabolic changes (interictal ¹⁸ F-fluorodeoxyglucose PET) of these patients in comparison with (1) healthy subjects with similar age and sex distribution (n = 19) using whole-brain voxel-based analysis (p-voxel < .001, p-cluster < .05, uncorrected) and (2) patients without IA with similar age and seizure onset zone (n = 55). We found 12 patients with IA. Epilepsy was mainly temporal (four right temporal mesial, four bitemporal, two left temporal lateral, one right temporal lateral, and one right temporal “plus”). Seven patients had negative magnetic resonance imaging. Whole-brain statistical analysis of PET imaging was performed at the voxel level, showing that in comparison to healthy subjects and to epileptic patients without IA, a hypometabolism in the right posterior insula characterized epileptic patients with IA. Our study suggests involvement of the right posterior insula-a part of the central autonomic network-in the pathophysiological mechanism of IA.

PMID:34227678 | DOI:10.1111/epi.16981

Br J Surg. 2021 Jul 6:znab234. doi: 10.1093/bjs/znab234. Online ahead of print.

NO ABSTRACT

PMID:34227652 | DOI:10.1093/bjs/znab234

Hum Reprod. 2021 Jul 6:deab157. doi: 10.1093/humrep/deab157. Online ahead of print.

ABSTRACT

STUDY QUESTION: What are the knowledge and views of UK-based women towards egg donation (ED) and egg sharing (ES)?

SUMMARY ANSWER: Lacking knowledge of the practices of ED and ES could be an influential factor in donor egg shortages, rather than negative perceptions or lack of donor anonymity and financial incentives.

WHAT IS KNOWN ALREADY: The increasing age of women trying to conceive has led to donor egg shortages, with ED and ES failing to meet demand. Indeed, in recent years in the UK, ES numbers have fallen. This results in long waiting lists, forcing patients abroad for fertility treatment to take up cross border reproductive care. Previous research suggests a lack of knowledge of ED among members of the general public; however, no study has yet assessed knowledge or views of ES in the general public.

STUDY DESIGN, SIZE, DURATION: Six hundred and thirty-five UK-based women over 18 years were voluntarily recruited from social media community groups by convenience sampling. The recruitment period was from February to April 2020.

PARTICIPANTS/MATERIALS, SETTING, METHODS: Participants completed a previously validated questionnaire regarding female fertility, ED and ES, including knowledge, perceptions and approval of the practices and relevant legislation. This included ranking key benefits and issues regarding egg sharing. The questionnaire was completed using the online Qualtrics survey software. Statistical analysis was conducted using SPSS.

MAIN RESULTS AND THE ROLE OF CHANCE: Regarding knowledge of ED and ES, 56.3% and 79.8%, respectively had little or no prior knowledge. Upon explanation, most approved of ED (85.8%) and ES (70.4%). A greater proportion of respondents would donate to a family member/friend (49.75%) than to an anonymous recipient (35.80%). Overall, ES was viewed less favourably than ED, with ethical and practical concerns highlighted. Women aged 18-30 years were significantly more likely to approve of egg donation practice compared to those aged >30 years (P < 0.0001). Those against ES found fears of financial coercion or negative psychological wellbeing the most concerning. About 35.8% and 49.7% would personally consider anonymous and known ED, respectively, whilst 56.7% would consider ES. Those answering in favour of egg sharing were significantly more likely to give higher benefit ratings compared to those against the practice (P < 0.001). Most agreed (55.8%) with and were not deterred to donate (60.1%) by the ‘Disclosure of Donor Identity’ legislation. Only 31.6% agreed with the compensatory cap; however, 52.7% would not be more motivated to donate by an increased cap.

LIMITATIONS, REASONS FOR CAUTION: There were several limitations of the study, including the use of convenience sampling and the voluntary nature of participation opening the study up to sampling and participation bias. Finally, closed questions were predominantly used to allow the generation of quantitative data and statistical analysis. However, this approach prevented opinion justification and qualitative analysis, limiting the depth of conclusions drawn.

WIDER IMPLICATIONS OF THE FINDINGS: To our knowledge, this is the first study to survey the general public’s knowledge and views of ED/ES using a previously validated questionnaire. The conclusion that lack of knowledge could be contributing to the current donor shortfall in the UK demonstrates that campaigns to inform women of the practices are necessary to alleviate donor oocyte shortages.

STUDY FUNDING/COMPETING INTEREST(S): No external funds were used for this study. The authors have no conflicts of interest.

TRIAL REGISTRATION NUMBER: NA.

PMID:34227667 | DOI:10.1093/humrep/deab157

Ann Hepatobiliary Pancreat Surg. 2021 Jun 30;25(Suppl 1):S186. doi: 10.14701/ahbps.LV-PP-2-5.

ABSTRACT

INTRODUCTION: Adult-to-adult living donor liver transplantation (LDLT) has been a dominant type of liver transplantation, especially in Asian countries where deceased donors are extremely scarce. Several centers have been attempted to use left liver graft because it could reduce the postoperative risk to the donor. This study retrospectively compared clinical outcomes between right and left liver grafts in adult-to-adult LDLT.

METHODS: All consecutive 116 patients who underwent adult-to-adult LDLT between 2010 and 2020 were enrolled in this study. The study cohort comprised of 94 patients in the right liver (RL) group and 22 in the left liver (LL) group. When both hemiliver grafts meet the selection criteria, LL graft was preferred. Prospectively collected clinicopathologic characteristics, perioperative outcomes, and survival were evaluated.

RESULTS: In terms of donor variables, median actual graft-to-recipient weight ratio was higher in the RL group than in the LL group (1.01 [0.66-1.66] vs. 0.85 [0.63-1.50], p = 0.030). Total bilirubin level and prothrombin time on postoperative day 5 were worse in the RL group, but it did not reach statistical significance. In terms of recipient variables, hepatic venous pressure gradient after reperfusion was comparable between the groups. The 90-day complication (above Clavien-Dindo grade IIIA) and 1-year graft survival rates were not different between the RL and LL groups (35.9% vs. 56.2%, p = 0.123; 91.3% vs. 93.8%, p = 0.744; respectively).

CONCLUSIONS: This study demonstrated comparable donor and recipient outcomes between the RL and LL groups. In an effort to minimize potential donor risk, LL graft is worth considering when both grafts meet the selection criteria.

PMID:34227546 | DOI:10.14701/ahbps.LV-PP-2-5

Ann Hepatobiliary Pancreat Surg. 2021 Jun 30;25(Suppl 1):S189. doi: 10.14701/ahbps.LV-PP-3-2.

ABSTRACT

INTRODUCTION: Caudate lobes are anatomically located between the hepatic hilum and inferior vena cava. Isolated caudate lobectomy is still a challenging procedure for hepatobiliary pancreas surgeons because it is quite complicated depending on the relationship between the surrounding major vascular structures and the biliary tract. In this study, we introduce a various surgical strategy for hepatocellular carcinoma located in the caudate lobe, and report the results.

METHODS: From January 2005 to December 2015, 35 patients who underwent caudate lobectomy due to hepatocellular carcinoma in Seoul National University Hospital were enrolled. We described several surgical strategies with hanging maneuver and compared the clinical outcomes between the radical resection group and the local resection group.

RESULTS: A total of 35 patients underwent hepatectomy including the caudate lobe. The median follow-up period was 86.7 months (3.8-183.6 months). There was 2 (5.7%) extended right hemihepatectomy, 2 (5.7%) extended left hemihepatectomy, 2 (5.7%) right posterior sectionectomy including caudate lobe, 12 (34.3%) cases of isolate caudate lobectomy, and 15 (42.9%) cases of local tumorectomy (non-anatomical). There was no statistically significant differences were observed in operative time, hospital stay, and complication rate (mean, 247.1 ± 104.7 minutes vs. 247.1 ± 104.7 minutes, p = 0.729; mean, 10.2 ± 6.68 days vs. 10.2 ± 6.14 days, p = 1.000). The rates of recurrence were significantly lower in the radical resection groups than in the local resection group (13/15, 86.7% vs. 10/20, 50.0%; p = 0.034).

CONCLUSIONS: Various surgical strategies are necessary to resect caudate tumors depending on the location and degree of invasion. These several methods would be helpful to reduce recurrence without complications.

PMID:34227549 | DOI:10.14701/ahbps.LV-PP-3-2

Genet Mol Biol. 2021 Jul 2;44(3):e20200349. doi: 10.1590/1678-4685-GMB-2020-0349. eCollection 2021.

ABSTRACT

This study aimed to elucidate the anti-inflammatory and antioxidant properties of resveratrol (RSV) in human gingival fibroblasts (HGFs) following stimulation by P. gingivalis lipopolysaccharide (LPS). The levels of the inflammatory cytokines IL-1β, IL-6, IL-8 and TNFα, the activity of the antioxidant enzymes SOD and GSH-Px, and the levels of MDA, were evaluated by ELISA. It was observed that the expression of IL-1β, IL-6, IL-8 and TNFα in LPS-induced HGFs was significantly downregulated by RSV in a dose-dependent manner. RSV also partly increased oxidative stress (OS)-related factors, including SOD and GSH-Px, which was accompanied by a decrease in MDA production, although the results were not statistically significant. Additionally, RSV-induced deactivation of the PI3K/AKT and Wnt/β-catenin pathways in LPS-induced HGFs was observed by western blot analysis. Subsequently, it was demonstrated treatment with PI3K/AKT pathway inhibitor (LY294002) or Wnt/β-catenin pathway inhibitor (Dickkopf-1, DKK-1) could further enhance the anti-inflammatory and antioxidant effects of RSV by downregulating the expression of IL-1β, IL-6, IL-8 and TNFα, and the production of MDA, and increasing the activity of SOD and GSH-Px in LPS-induced HGFs. These results suggested RSV attenuated the inflammation and OS injury of P. gingivalis LPS-treated HGFs by deactivating the PI3K/AKT and Wnt/β-catenin signaling pathways.

PMID:34227646 | DOI:10.1590/1678-4685-GMB-2020-0349

Ann Hepatobiliary Pancreat Surg. 2021 Jun 30;25(Suppl 1):S182. doi: 10.14701/ahbps.LV-PP-2-1.

ABSTRACT

INTRODUCTION: For the APRI and FIB-4 index, which are one of the non-invasive methods of examining the degree of liver fibrosis, our paper aims to examine the implications for predicting the prognosis in hepatocellular carcinoma patients undergoing hepatectomy.

METHODS: Between 2006 and 2013, total 973 patients were underwent hepatic resection due to hepatocellular carcinoma and 871 patients were enrolled in our study after adjusting exclusion criteria. Statistics were performed by calculating the optimal cut off values for the recurrence free survival and overall survival of each group which are categorized by etiology and multivariate analysis were performed for evaluating the performance of index.

RESULTS: Among the causes of HCC patients, HBV (n = 629, 72%) was the most common, and men were dominant in all groups. In each group divided by etiology, the area under the receiver operating characteristics of APRI and FIB-4 for recurrence free survival and overall survival were relatively higher in HCV patients than in other groups. After setting the cut-off value through the Youden index, univariate analysis and multivariate analysis for RFS and OS of all groups were performed, and the results of APRI values for RFS in each group were statistically significant (HBV : OR = 1.849, p = 0.001; HCV : OR = 6,548, p = 0.010; Alcohol : OR = 3.393, p = 0.004).

CONCLUSIONS: The significance of this study is that these simple laboratory findings are meaningful in revealing the prognosis of HCC patients, which can be predicted accurately only after the pathologic staging after surgery.

PMID:34227542 | DOI:10.14701/ahbps.LV-PP-2-1

Ann Hepatobiliary Pancreat Surg. 2021 Jun 30;25(Suppl 1):S181. doi: 10.14701/ahbps.LV-PP-1-6.

ABSTRACT

INTRODUCTION: Depending on the recipient’s condition and lack of donors, even liver grafts with poor conditions may need to be transplanted. This study was conducted to analyze the outcomes after receiving a liver graft that abandoned transplantation due to poor graft conditions at the preceding centers.

METHODS: From January 2010 to September 2020, deceased-donor liver transplantation (DDLT) was performed in 161 patients in our center. Among them, 127 patients (allocated group) were preferentially allocated to our center by KONOS and the remaining 34 patients (abandoned group) received liver grafts that were abandoned by other transplant centers due to poor organ conditions. Various perioperative factors and postoperative outcomes were compared.

RESULTS: There was no difference in recipient factors before transplantation, and the donor had a longer stay in the ICU in the abandoned group. The operation time was less in the abandoned group, but there was no statistical difference (p = 0.06), and there was no difference in ischemic time or transfusion between the two groups. Postoperative ICU hospital stay was longer in the abandoned group (p = 0.04), but postoperative in-hospital mortality was not different between the two groups. There was no difference between the two groups in long term survival after transplantation.

CONCLUSIONS: Even if the graft that was abandoned due to poor condition, good results can be obtained if the transplant is carried out according to the recipient state. And as a result, it is expected that the discarded graft can be reduced.

PMID:34227541 | DOI:10.14701/ahbps.LV-PP-1-6