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Nevin Manimala Statistics

Comparison of Simulated and True Keratometry Measurements Using Swept-Source Optical Coherence Tomography and Dual Scheimpflug-Placido Imaging

J Ophthalmol. 2021 Sep 16;2021:5860846. doi: 10.1155/2021/5860846. eCollection 2021.

ABSTRACT

PURPOSE: To compare simulated and total keratometry and corneal astigmatism values between the IOLMaster 700 and Galilei G4 devices.

METHODS: A retrospective chart review was conducted for all patients undergoing phacoemulsification by a single surgeon (RTP) from March through September 2020 and who underwent imaging with both the IOLMaster 700 and Galilei G4. Exclusion criteria were prior corneal surgery, keratectatic diseases and inability to obtain a reliable image during image acquisition. Mean, flat, and steep keratometry values as well as astigmatism magnitude were compared.

RESULTS: A total of 200 eyes of 100 patients were included. Intraclass correlation coefficients (ICC) were moderate or high for all variables. Mean difference ± SD in SimK and TrueK between devices (G4-IOLM) was 0.05 ± 0.318 diopters and -1.1156 ± 0.438 diopters, respectively (p < 0.05 for both). The IOLM measured steeper TrueK value than the G4. For SimK, there was a statistically significant difference between devices only for mean keratometry (K), whereas for TrueK, there were significant differences in flat K, steep K, and mean K. Astigmatism analysis revealed a difference in mean (±SD) SimK of 0.07 (±0.57) D at 94 degrees and in mean TrueK of 0.04 (±0.85) D at 108 degrees.

CONCLUSION: Though there is overall good correlation between the IOLMaster 700 and Galilei G4 in SimK and astigmatism measurements, there is a significant difference in TrueK measurements, with the IOLM measuring steeper values by about 1.0 diopter as compared to the G4.

PMID:34567799 | PMC:PMC8460384 | DOI:10.1155/2021/5860846

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Nevin Manimala Statistics

Endoscopic treatment of iliopsoas impingement after total hip arthroplasty: a minimum 2-year follow-up and comparison of tenotomy performed at the acetabular rim versus lesser trochanter

J Hip Preserv Surg. 2021 May 11;8(1):83-89. doi: 10.1093/jhps/hnab035. eCollection 2021 Jan.

ABSTRACT

Iliopsoas impingement is an underdiagnosed cause of groin pain after total hip arthroplasty (THA), being responsible for 4.4% of cases. Non-surgical treatment may be effective in ∼50% of cases. Endoscopic surgery has gained popularity as an option for non-responsive patients because of its non-invasive characteristics, faster recovery and encouraging results. This study compares two different sites of endoscopic psoas tenotomy performed following THA: at the edge of the acetabulum (AR) versus at the lesser trochanter (LT). This is a retrospective review of prospectively collected data from a single-surgeon case series. Thirty-five iliopsoas tenotomy cases which had >24-month follow-up were identified. There were 21 tenotomies at the lesser trochanter. Demographic data, preop and postop pain, mHHS and NAHS scores, strength and patient satisfaction data were collected and analysed. Average age at the time of surgery was 62. Mean follow-up for the LT group was 49.11 months and 42.42 months for the AR group. Pain decreased significantly for both groups (P < 0.001). Both mHHS and NAHS showed superiority in the LT group, but this difference did not reach significance (P = 0.06). LT patients showed better strength with 71.42% of them having normal strength at latest follow-up, compared with 41.6% in the AR group. There were no complications in either group. Endoscopic tenotomy is a safe and reliable surgical option, giving significant pain relief and good functional outcomes. Tenotomy at the level of the lesser trochanter might be preferable since it shows better outcomes. Larger studies are necessary to achieve statistically significant results.

PMID:34567604 | PMC:PMC8460172 | DOI:10.1093/jhps/hnab035

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Nevin Manimala Statistics

Fusing MEMS technology with lab-on-chip: nanoliter-scale silicon microcavity arrays for digital DNA quantification and multiplex testing

Microsyst Nanoeng. 2020 Oct 5;6:82. doi: 10.1038/s41378-020-00187-1. eCollection 2020.

ABSTRACT

We report on the development of a microfluidic multiplexing technology for highly parallelized sample analysis via quantitative polymerase chain reaction (PCR) in an array of 96 nanoliter-scale microcavities made from silicon. This PCR array technology features fully automatable aliquoting microfluidics, a robust sample compartmentalization up to temperatures of 95 °C, and an application-specific prestorage of reagents within the 25 nl microcavities. The here presented hybrid silicon-polymer microfluidic chip allows both a rapid thermal cycling of the liquid compartments and a real-time fluorescence read-out for a tracking of the individual amplification reactions taking place inside the microcavities. We demonstrate that the technology provides very low reagent carryover of prestored reagents < 6 × 10-2 and a cross talk rate < 1 × 10-3 per PCR cycle, which facilitate a multi-targeted sample analysis via geometric multiplexing. Furthermore, we apply this PCR array technology to introduce a novel digital PCR-based DNA quantification method: by taking the assay-specific amplification characteristics like the limit of detection into account, the method allows for an absolute gene target quantification by means of a statistical analysis of the amplification results.

PMID:34567692 | PMC:PMC8433415 | DOI:10.1038/s41378-020-00187-1

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Nevin Manimala Statistics

Arthroscopic utilization of ChondroFiller gel for the treatment of hip articular cartilage defects: a cohort study with 12- to 60-month follow-up

J Hip Preserv Surg. 2021 Jul 31;8(1):22-27. doi: 10.1093/jhps/hnab002. eCollection 2021 Jan.

ABSTRACT

ChondroFiller gel is an absorbable collagen implant. It serves as a protective cover for the cartilage defects, allowing chondrocyte migration into the lesion. The implant consists of collagen (Type I) and is derived from veterinary monitored rats. This study evaluates the use of ChondroFiller gel in the treatment of cartilage lesions during hip joint arthroscopy. A prospective study was conducted on a group of 26 adult patients. All patients had an existing femoroacetabular impingement together with acetabular cartilage lesions >2 cm2. All patients underwent hip arthroscopic surgery and the lesions were treated using ChondroFiller gel. The cartilage tissue healing was evaluated postoperatively using MRI. A total of 26 patients, including 5 females and 21 males, all with articular cartilage lesions, were included in the study. Cartilage healing conditions were evaluated for all patients, and the difference between pre- and post-surgery conditions was statistically significant. The follow-up scores have been acquired from 21 out of initial 26 patients (2 were disqualified after receiving THR, 3 could not be reached by researchers) after 3, 4 and 5 years consecutively with 17/21 patients having good/excellent results. The use of ChondroFiller gel during arthroscopy of the hip for acetabular cartilage lesions is an effective treatment technique. Encouraging long-term results have been observed, but further research on larger group of patient is required to better assess the full value of this technique. Patients with pre-existing osteoarthritis (Tönnis 2-3) have poor results.

PMID:34567597 | PMC:PMC8460160 | DOI:10.1093/jhps/hnab002

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Nevin Manimala Statistics

Rear drop: a new radiographic landmark for estimation of pelvic tilt on pelvis AP radiographs

J Hip Preserv Surg. 2021 May 5;8(1):58-66. doi: 10.1093/jhps/hnab037. eCollection 2021 Jan.

ABSTRACT

Estimation of pelvic tilt on anteroposterior (AP) pelvis radiograph is often done by indirect methods based on the midline pelvic landmarks. The purpose of this cadaveric study is to describe a new radiographic landmark and reference measurements to estimate the coronal tilt of the pelvis, independent of the midline references. The new radiologic reference is called ‘rear drop’, and its anatomic location is described with the cadaveric pelvis AP radiographs in various pelvic inclination. The parameters derived from the new reference were used to assess the pelvic tilt, and the results were compared with the previously established method using ‘sacrococcygeal joint to symphysis distance’ (SCSD). The shape of the new figure is used to determine the position of the pelvis, and its relationship with the previously described acetabular retroversion indicators was statistically analyzed. The new reference figure corresponds to the posteroinferior edge of the horseshoe shape of the acetabular margin. The newly derived reference parameters, rear to tear distance and rear to tear angle, changes with pelvic tilt and are strongly correlated with SCSD. The shape of the rear drop changes with the changing pelvic tilt and correlates statistically with the previously described acetabular retroversion indicators. Rear drop and its derivative measurements can be used as a reliable and reproducible indicator to estimate the coronal pelvic tilt, free of midline reference points. This new reference will be a base for future clinical studies on pelvic tilt, rotation and their application in intraoperative hip fluoroscopy.

PMID:34567601 | PMC:PMC8460171 | DOI:10.1093/jhps/hnab037

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Nevin Manimala Statistics

Estimating the drivers of urban economic complexity and their connection to economic performance

R Soc Open Sci. 2021 Sep 22;8(9):210670. doi: 10.1098/rsos.210670. eCollection 2021 Sep.

ABSTRACT

Estimating the capabilities, or inputs of production, that drive and constrain the economic development of urban areas has remained a challenging goal. We posit that capabilities are instantiated in the complexity and sophistication of urban activities, the know-how of individual workers, and the city-wide collective know-how. We derive a model that indicates how the value of these three quantities can be inferred from the probability that an individual in a city is employed in a given urban activity. We illustrate how to estimate empirically these variables using data on employment across industries and metropolitan statistical areas in the USA. We then show how the functional form of the probability function derived from our theory is statistically superior when compared with competing alternative models, and that it explains well-known results in the urban scaling and economic complexity literature. Finally, we show how the quantities are associated with metrics of economic performance, suggesting our theory can provide testable implications for why some cities are more prosperous than others.

PMID:34567588 | PMC:PMC8456143 | DOI:10.1098/rsos.210670

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Nevin Manimala Statistics

Verification of the accuracy of the SIR model in forecasting based on the improved SIR model with a constant ratio of recovery to infection rate by comparing with monitored second wave data

R Soc Open Sci. 2021 Sep 22;8(9):211379. doi: 10.1098/rsos.211379. eCollection 2021 Sep.

ABSTRACT

The temporal evolution of second and subsequent waves of epidemics such as Covid-19 is investigated. Analytic expressions for the peak time and asymptotic behaviours, early doubling time, late half decay time, and a half-early peak law, characterizing the dynamical evolution of number of cases and fatalities, are derived, where the pandemic evolution exhibiting multiple waves is described by the semi-time SIR model. The asymmetry of the epidemic wave and its exponential tail are affected by the initial conditions, a feature that has no analogue in the all-time SIR model. Our analysis reveals that the immunity is very strongly increasing in several countries during the second Covid-19 wave. Wave-specific SIR parameters describing infection and recovery rates we find to behave in a similar fashion. Still, an apparently moderate change of their ratio can have significant consequences. As we show, the probability of an additional wave is however low in several countries due to the fraction of immune inhabitants at the end of the second wave, irrespective of the ongoing vaccination efforts. We compare with alternate approaches and data available at the time of submission. Most recent data serves to demonstrate the successful forecast and high accuracy of the SIR model in predicting the evolution of pandemic outbreaks as long as the assumption underlying our analysis, an unchanged situation of the distribution of variants of concern and the fatality fraction, do not change dramatically during a wave. With the rise of the α variant at the time of submission the second wave did not terminate in some countries, giving rise to a superposition of waves that is not treated by the present contribution.

PMID:34567593 | PMC:PMC8456141 | DOI:10.1098/rsos.211379

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Nevin Manimala Statistics

Validation of a contact-free sleep apnea monitor in adults with obstructive sleep apnea

Zhonghua Jie He He Hu Xi Za Zhi. 2021 Oct 12;44(10):880-885. doi: 10.3760/cma.j.cn112147-20210131-00088.

ABSTRACT

Objective: To evaluate the diagnostic value of a contact-free sleep apnea monitor in Chinese adults with obstructive sleep apnea (OSA). Methods: One hundred and ninety-eight participants with snoring were recruited between July 2018 and May 2019 in Sleep Center of Peking University People’s Hospital, using nocturnal polysomnography (PSG) and contact-free sleep apnea monitor simultaneously. We evaluated the difference between respiratory event index (REI) generated by contact-free sleep apnea monitor and PSG-Apnea-Hypopnea Index (AHI). We calculated the sensitivity and specificity of OSA diagnosis using the contact-free sleep apnea monitor by hypothesis testing for means, Pearson correlation coefficient and Bland-Altman plots. Then, we used the receiver operating characteristic (ROC) curve to find out the best cut-off of OSA diagnosis. Results: PSG-AHI and the REI of contact-free sleep apnea monitor showed no statistically significant difference [15.9 (4.7, 40.2) vs. 16.2 (6.1, 40.0), P=0.381], and they were significantly correlated (r=0.914, P<0.05), with mean difference of -0.06 (95%CI:-18.44, 18.31). The ROC curve showed that if REI ≥5 events/h was used as diagnostic criteria, the sensitivity and specificity of diagnosing OSA were 91.2% and 58.0%, respectively. The sensitivity and specificity of the contact-free sleep apnea monitor REI≥13.3 in diagnosing moderate and severe OSA were 90.1% and 71.1%, respectively. Conclusion: The REI obtained from the contact-free sleep apnea monitor showed a good agreement with the PSG-AHI, and therefore, the contact-free sleep apnea monitor can be used for the screening of patients with moderate and severe OSA.

PMID:34565114 | DOI:10.3760/cma.j.cn112147-20210131-00088

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Nevin Manimala Statistics

Etiology of severe community-acquired pneumonia in immunocompromised patients

Zhonghua Jie He He Hu Xi Za Zhi. 2021 Oct 12;44(10):892-896. doi: 10.3760/cma.j.cn112147-20210131-00087.

ABSTRACT

Objective: To analyze the etiology of severe community-acquired pneumonia (SCAP) in immunocompromised patients, and to investigate the relationship between underlying diseases and infectious microorganisms. Methods: A retrospective analysis was performed on SCAP in immunocompromised patients admitted to the Fourth Department of Respiratory and Critical Medicine (MICU) of China-Japan Friendship Hospital from January 1, 2017 to December 31, 2019. A total of 119 SCAP patients were finally enrolled, including 65 males (54.6%), with an average age of (59.3±14.5) years. The average of Sequential Organ Failure Assessment (SOFA) score was 6.7±3.6 and the acute physiology and chronic health evaluation (APACHE) Ⅱ score was 19.4±6.8. Sixty (50%) of these patients were finally improved and discharged. Long-term glucocorticoid treatment was the main risk factor for immunocompromise. The difference of pathogenic microorganisms between patients with and without structural lung diseases, and the influence of different pathogenic microorganisms on hospital mortality were calculated, respectively. P<0.05 was considered to be statistically significant. Results: In this study, 99 (83.2%) patients were identified to have positive etiological results, and the incidence of concurrent infection was 54.5%. The top three pathogens were Pneumocystis Jiroveci (55.6%), Cytomegalovirus (47.5%) and Aspergillus (23.2%). Staphylococcus aureus was the most common bacterium, followed by Pseudomonas aeruginosa and Klebsiella pneumoniae. The risk of Pneumocystis Jiroveci infection was significantly higher in patients without underlying lung diseases as compared to those with underlying lung diseases (64.3% vs. 44.2%, P = 0.046). The in-hospital mortality was not different among patients infected with different pathogens(all P>0.05), but was higher in those with mixed infections(56.7% vs. 33.9%, P=0.013). Conclusions: Pneumocystis Jiroveci and Cytomegalovirus were the most common pathogens in immunocompromised patients with severe community-acquired pneumonia, and the incidence of Pneumocystis Jiroveci was significantly higher in patients without underlying lung diseases.

PMID:34565116 | DOI:10.3760/cma.j.cn112147-20210131-00087

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Nevin Manimala Statistics

Association of polymorphisms in endothelial dysfunction-related genes with susceptibility to essential hypertension in elderly Han population in Liaoning province, China

Rev Cardiovasc Med. 2021 Sep 24;22(3):895-901. doi: 10.31083/j.rcm2203096.

ABSTRACT

Hypertension is a complex disease which is mainly influenced by genetic factors. Recently, genome-wide association study (GWAS) found three novel endothelial dysfunction-related sites: Vascular endothelial growth factor A (VEGFA) rs9472135, Faciogenital dysplasia 5 (FGD5) rs11128722, Zinc Finger C3HC-type Containing 1 (ZC3HC1) rs11556924. Endothelial dysfunction is one of the early events in pathophysiology of essential hypertension. To investigate the association of endothelial dysfunction-related genes with essential hypertension, we conducted a case-control study of 431 patients with hypertension and 345 controls. The polymorphisms were detected using Taqman Probe. The alleles and genotypes of ZC3HC1 rs11556924 and VEGFA rs9472135 were not statistically different between the two groups, while the allele of FGD5 rs11128722 was different [P = 0.045, OR = 1.265, 95% CI = (1.009-1.586)], especially in the male [P = 0.035, OR = 1.496, 95% CI = (1.037-2.158)]. Analyzing the different of genotype distribution of 3 SNPs in the two groups under different genetic models, the genotypes of FGD5 rs11128722 showed difference in male under dominant model [P = 0.049, OR = 1.610, 95% CI = (1.018-2.544)]. The polymorphism of FGD5 rs11128722 had a significant difference in Body Mass Index (BMI) among different genotypes; In the additive genetic model, BMI of GA genotype was higher than that of GG (P = 0.038); GA + AA was higher than GG in the dominant genetic model (P = 0.011). In our study, we found that the polymorphisms of VEGFA rs9472135 and ZC3HC1 rs11556924 may not significantly associated with the risk of essential hypertension, and FGD5 rs11128722 may increase the risk of it, especially in elderly men.

PMID:34565088 | DOI:10.31083/j.rcm2203096