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Nevin Manimala Statistics

The influence of aging on the fracture load of milled monolithic crowns

BMC Oral Health. 2022 Nov 19;22(1):516. doi: 10.1186/s12903-022-02529-z.

ABSTRACT

BACKGROUND: This in-vitro study was conducted to assess the effect of aging on the fracture load of molar crowns fabricated with monolithic CAD/CAM materials.

METHODS: The crown restorations were produced from Cerasmart, Vita Enamic, and IPS e.max CAD blocks. Aging was applied to the 10 samples each of monolithic CAD/CAM materials (n = 10). Dual-axis chewing simulator (50 N, 1.1 Hz, lateral movement: 1 mm, mouth opening: 2 mm, 1,200,000 cycles) and thermocycling (± 5-55 °C, 6000 cycles) were applied as an aging procedure. 10 samples each of monolithic CAD/CAM materials without aging (n = 10) were considered the control group. 6 tested groups were obtained. Then, all samples were evaluated in a universal testing machine to determine the fracture loading values’.

RESULTS: There was not a statistically significant difference between the fracture load values before and after aging for all samples of Cerasmart, Vita Enamic, and IPS e.max CAD (p > 0.005). In a comparison of the monolithic materials together, a statistically significant difference was found between the fracture load values of IPS e.max CAD and Vita Enamic crowns before aging (p = 0.02). Also, Vita Enamic crowns (1978,71 ± 364,05 N) were found different from the IPS e.max CAD (p = 0.005) and Cerasmart crowns (p = 0.041) after aging.

CONCLUSIONS: Dynamic aging with 1.200.000 cycles was found to have no effect to fracture loading on milled Cerasmart, Vita Enamic, and IPS e.max CAD monolithic crowns.

PMID:36402987 | DOI:10.1186/s12903-022-02529-z

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Nevin Manimala Statistics

Efficacy and safety of heparin plus dexamethasone after partial splenic embolization for liver cirrhosis with massive splenomegaly

BMC Gastroenterol. 2022 Nov 19;22(1):470. doi: 10.1186/s12876-022-02580-8.

ABSTRACT

PURPOSE: The aim of this study was to investigate the efficacy and safety of the combination of low-molecular-weight heparin + dexamethasone after partial splenic embolization in cirrhotic patients with massive splenomegaly.

METHODS: This study included 116 patients with liver cirrhosis complicated with massive splenomegaly who underwent PSE in Union Hospital from January 2016 to December 2019, and they met the criteria. They were divided into two groups: PSE + Hep + Dex group (N = 54) and PSE group (N = 62). We conducted a retrospective study to analyze the efficacy and safety of the two groups of patients.

RESULTS: The volume of splenic embolization was 622.34 ± 157.06 cm3 in the PSE + Hep + DEX group and 587.62 ± 175.33 cm3 in the PSE group (P = 0.306). There was no statistically difference in the embolization rate of the spleen between the two groups (P = 0.573). WBC peaked 1 week after PSE and PLT peaked 1 month after PSE in both groups; it gradually decreased later, but was significantly higher than the preoperative level during the 12-month follow-up period. The incidences of abdominal pain (46.3% vs 66.1%, P = 0.039), fever (38.9% vs 75.8%, P < 0.001), PVT (1.9% vs 12.9%, P = 0.026), refractory ascites (5.6% vs 19.4%, P = 0.027) were lower in the PSE + Hep + DEX group than in the PSE group. The VAS score of abdominal pain in PSE group was higher than that in PSE + Hep + DEX group on postoperative days 2-8 (P < 0.05). Splenic abscess occurred in 1(1.6%) patient in the PSE group and none (0.0%) in the PSE + Hep + DEX group (P = 0.349).

CONCLUSIONS: The combined use of dexamethasone and low-molecular-weight heparin after PSE is a safe and effective treatment strategy that can significantly reduce the incidence of complications after PSE (such as post-embolization syndrome, PVT, refractory ascites).

PMID:36402985 | DOI:10.1186/s12876-022-02580-8

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Nevin Manimala Statistics

Methods for handling missing data in serially sampled sputum specimens for mycobacterial culture conversion calculation

BMC Med Res Methodol. 2022 Nov 19;22(1):297. doi: 10.1186/s12874-022-01782-8.

ABSTRACT

BACKGROUND: The occurrence and timing of mycobacterial culture conversion is used as a proxy for tuberculosis treatment response. When researchers serially sample sputum during tuberculosis studies, contamination or missed visits leads to missing data points. Traditionally, this is managed by ignoring missing data or simple carry-forward techniques. Statistically advanced multiple imputation methods potentially decrease bias and retain sample size and statistical power.

METHODS: We analyzed data from 261 participants who provided weekly sputa for the first 12 weeks of tuberculosis treatment. We compared methods for handling missing data points in a longitudinal study with a time-to-event outcome. Our primary outcome was time to culture conversion, defined as two consecutive weeks with no Mycobacterium tuberculosis growth. Methods used to address missing data included: 1) available case analysis, 2) last observation carried forward, and 3) multiple imputation by fully conditional specification. For each method, we calculated the proportion culture converted and used survival analysis to estimate Kaplan-Meier curves, hazard ratios, and restricted mean survival times. We compared methods based on point estimates, confidence intervals, and conclusions to specific research questions.

RESULTS: The three missing data methods lead to differences in the number of participants achieving conversion; 78 (32.8%) participants converted with available case analysis, 154 (64.7%) converted with last observation carried forward, and 184 (77.1%) converted with multiple imputation. Multiple imputation resulted in smaller point estimates than simple approaches with narrower confidence intervals. The adjusted hazard ratio for smear negative participants was 3.4 (95% CI 2.3, 5.1) using multiple imputation compared to 5.2 (95% CI 3.1, 8.7) using last observation carried forward and 5.0 (95% CI 2.4, 10.6) using available case analysis.

CONCLUSION: We showed that accounting for missing sputum data through multiple imputation, a statistically valid approach under certain conditions, can lead to different conclusions than naïve methods. Careful consideration for how to handle missing data must be taken and be pre-specified prior to analysis. We used data from a TB study to demonstrate these concepts, however, the methods we described are broadly applicable to longitudinal missing data. We provide valuable statistical guidance and code for researchers to appropriately handle missing data in longitudinal studies.

PMID:36402979 | DOI:10.1186/s12874-022-01782-8

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Nevin Manimala Statistics

Value of sputum Gram stain, sputum culture, and bronchoalveolar lavage fluid Gram stain in predicting single bacterial pathogen among children with community-acquired pneumonia

BMC Pulm Med. 2022 Nov 19;22(1):427. doi: 10.1186/s12890-022-02234-1.

ABSTRACT

BACKGROUND: Currently, the microbial etiology of community-acquired pneumonia in children remains challenging. While Gram stain and sputum culture are commonly used to detect bacterial pathogens, it is unclear whether these approaches can predict single pathogen from bronchoalveolar lavage fluid (BALF) culture.

METHODS: A retrospective study involving 287 children hospitalized for pneumonia was conducted. Sputum specimens were collected on admission; and BALF specimens were collected within 24 h after admission. Taking BALF culture as the reference standard, the sensitivity and specificity of Sputum Gram stain (SGS), sputum culture, and BALF Gram stain (BGS) were calculated. The agreement between these approaches and BALF culture was compared using kappa statistics.

RESULTS: For SGS, the specificity was 23%. The overall sensitivity was 70%, including 87% for Gram-positive (G+) cocci, 56% for Gram-negative (G-) cocci, and 50% for G-bacilli. For sputum culture, the specificity was 70%. The overall sensitivity was 64%, including 71% for Streptococcus pneumoniae, 71% for Moraxella catarrhalis, and 64% for Haemophilus influenzae. For BGS, the specificity was 71%. The overall sensitivity was 60%, including 77% for G+cocci, 38% for G-cocci, and 44% for G-bacilli. While SGS had poor agreement with BALF culture, both sputum culture and BGS had moderate agreement with BALF culture.

CONCLUSIONS: Both sputum culture and BGS are helpful in predicting single bacterial pathogen from BALF culture among children with community-acquired pneumonia. Sputum cultures and BGS can provide early clues for BALF pathogen when BALF culture results are pending or bronchoscopy is not performed.

PMID:36402959 | DOI:10.1186/s12890-022-02234-1

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Nevin Manimala Statistics

SeSAM: software for automatic construction of order-robust linkage maps

BMC Bioinformatics. 2022 Nov 19;23(1):499. doi: 10.1186/s12859-022-05045-7.

ABSTRACT

BACKGROUND: Genotyping and sequencing technologies produce increasingly large numbers of genetic markers with potentially high rates of missing or erroneous data. Therefore, the construction of linkage maps is more and more complex. Moreover, the size of segregating populations remains constrained by cost issues and is less and less commensurate with the numbers of SNPs available. Thus, guaranteeing a statistically robust marker order requires that maps include only a carefully selected subset of SNPs.

RESULTS: In this context, the SeSAM software allows automatic genetic map construction using seriation and placement approaches, to produce (1) a high-robustness framework map which includes as many markers as possible while keeping the order robustness beyond a given statistical threshold, and (2) a high-density total map including the framework plus almost all polymorphic markers. During this process, care is taken to limit the impact of genotyping errors and of missing data on mapping quality. SeSAM can be used with a wide range of biparental populations including from outcrossing species for which phases are inferred on-the-fly by maximum-likelihood during map elongation. The package also includes functions to simulate data sets, convert data formats, detect putative genotyping errors, visualize data and map quality (including graphical genotypes), and merge several maps into a consensus. SeSAM is also suitable for interactive map construction, by providing lower-level functions for 2-point and multipoint EM analyses. The software is implemented in a R package including functions in C++.

CONCLUSIONS: SeSAM is a fully automatic linkage mapping software designed to (1) produce a framework map as robust as desired by optimizing the selection of a subset of markers, and (2) produce a high-density map including almost all polymorphic markers. The software can be used with a wide range of biparental mapping populations including cases from outcrossing. SeSAM is freely available under a GNU GPL v3 license and works on Linux, Windows, and macOS platforms. It can be downloaded together with its user-manual and quick-start tutorial from ForgeMIA (SeSAM project) at https://forgemia.inra.fr/gqe-acep/sesam/-/releases.

PMID:36402957 | DOI:10.1186/s12859-022-05045-7

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Nevin Manimala Statistics

Allogeneic hematopoietic cell transplantation for myelodysplastic syndrome unclassifiable – a retrospective study on behalf of the Chronic Malignancies Working Party of the EBMT

Bone Marrow Transplant. 2022 Nov 19. doi: 10.1038/s41409-022-01870-9. Online ahead of print.

NO ABSTRACT

PMID:36402922 | DOI:10.1038/s41409-022-01870-9

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Nevin Manimala Statistics

Improving the accuracy of estimates of the pulse sequence period using the methodology of complete sufficient statistics

Sci Rep. 2022 Nov 19;12(1):19932. doi: 10.1038/s41598-022-24457-2.

ABSTRACT

This paper is devoted to the synthesis of new signal processing algorithms based on the methodology of complete sufficient statistics and the possibility of using the Lehmann-Scheffe theorem. Using the example of a sequence of quasi-rectangular pulses, an approach to estimating their period was illustrated, taking into account the duty-off factor and the pulse squareness coefficient. A mathematical model was developed, on the basis of which, estimates of the potential accuracy of the methods were carried out. It is established that for the sample size value (n > 8), the relative root-mean-square error of estimating the repetition period using the methodology of complete sufficient statistics is lower than that of the traditional estimate. In addition to theoretical calculations, simulation results confirming the achieved effect are presented. The results obtained have a wide range of applicability and can be used in the design of control and measuring equipment in the oil and gas industry, in the development of medical equipment, in the field of telecommunications, in the design of pulse-Doppler radars, etc.

PMID:36402901 | DOI:10.1038/s41598-022-24457-2

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Nevin Manimala Statistics

Efficacy and safety of the extraction of cardiostimulation leads using a mechanical dissection tool. A single center experience

Pacing Clin Electrophysiol. 2022 Nov 19. doi: 10.1111/pace.14625. Online ahead of print.

ABSTRACT

BACKGROUND: The percutaneous extraction of endovascular cardiostimulation and defibrillation leads is the most frequent technique nowadays. The tools used today must guarantee the success of the procedure, with the minimum of complications. Our objective was to analyze the safety and efficacy of lead extraction using the Evolution® mechanical dissection tool (Cook Medical, United States).

METHODS: A retrospective study was carried out in a total of 826 consecutive patients from October 2009 to December 2018 who underwent the procedure with the Evolution® mechanical dissection tool.Preoperative study included complete blood tests, echocardiogram, and chest X-ray. The procedures were performed in the operating room, under general anesthesia and echocardiographic control.

RESULTS: A total of 1227 leads were extracted with a mean chronicity of 10.3±5.1 years. Clinical success rate was 99.7%. A total of 16 (1.9%) complications occurred, 2 (0.24%) were major complications and 14 (1.7%) were minor complications. There was no operative mortality. There was no statistically significant relationship between implant chamber and complete efficacy. The complete extraction was achieved in all left ventricular leads, in 762 of 774 (98.45%) of right ventricular lead removal, and in 330 of 334 (98.8%) of right atrial leads (p = 0.31).

CONCLUSION: In our experience, percutaneous extraction of intravenous leads via the use of the Evolution® tool (Cook Medical, United States), is a very effective and safe technique that offers low morbidity and mortality. This article is protected by copyright. All rights reserved.

PMID:36401870 | DOI:10.1111/pace.14625

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Nevin Manimala Statistics

Analysis of risk factors for the development of infertility in men from infertile couples, depending on age.

Adv Gerontol. 2022;35(4):485-491.

ABSTRACT

According to the Russian Society of Urologists, the frequency of infertility in marriage in the Russian Federation is 8-17,2%; half of the cases are associated with the male factor. Among the risk factors for the development of male infertility, there are mainly medical reasons, lifestyle factors and negative environmental factors. Despite the fact that the problem of infertility is addressed by men of different ages, from youth to the elderly, the correction of risk factors is usually carried out without taking into account the age of the patient, which makes it difficult to develop a personalized strategy for the treatment or prevention of infertility. The aim of the study was to study the structure of the leading risk factors for the development of infertility in men from infertile couples, to identify and characterize their age-associated features. The analysis of the medical histories of 1 198 men from infertile couples and the collection of information on all available risk factors for infertility were carried out. The analysis of age features was performed by dividing the sample into 5 age groups: 1st (n=271) – men ≤29,9 years; 2nd (n=415) – 30-34,9 years; 3rd (n=291) – 35-39,9 years; 4th (n=141) – 40-44,9 years; 5th (n=80) – ≥45 years. It was shown that in the general sample of medical causes, factors associated with chronic inflammation predominate: sexually transmitted infections (STIs) – 54%; prostatitis – 32%; obesity – 27%; from non-medical: alcohol – 73%; stress – 47%; smoking – 41%. With increasing age, the frequency of obesity, STIs, prostatitis, hepatitis B/C, mumps increases statistically significantly, while the most unfavorable group of men is 40-45 years old for factors such as STIs, hepatitis B/C and mumps, and the group of men over 45 years old for factors such as obesity and prostatitis.

PMID:36401856

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Nevin Manimala Statistics

The course on the longevity of the population: the problem and the prospect.

Adv Gerontol. 2022;35(4):458-465.

ABSTRACT

The demographic situation of the Russian Federation is characterized by an aging population, which is a new challenge to achieve active and healthy longevity. The purpose of the study is to identify the factors influencing the increase in active longevity based on the results of the analysis of statistical data on the proportion of people over 60 years of age and life expectancy and sociological studies. On the basis of official statistics, the analysis of life expectancy, the proportion of people over 60 years old was carried out. The obtained data of the sociological study revealed that in order for the Russian Federation to follow the course of increasing active and healthy longevity, it must focus on the determinants of socio-economic character. On the basis of the age-shifting method, the forecast of the proportion of people over 60 years old was carried out (using the example of one of the regions of the Russian Federation). The Center for Family and Demography of the Academy of Sciences of the Republic of Tatarstan has developed recommendations for achieving active and healthy longevity, which are presented in the annual Demographic report of the Republic of Tatarstan, by improving health and reducing mortality.

PMID:36401852