Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

Isolation and biological analysis of tumor stem cells from pancreatic adenocarcinoma

AIM: To explore the method of isolation and biological analysis of tumor stem cells from pancreatic adenocarcinoma cell line PANC-1

Pylorus-Preserving Versus Pylorus-Resecting Pancreaticoduodenectomy for Periampullary and Pancreatic Carcinoma: A Meta-Analysis

<div><p>Background</p><p>The aim of this meta-analysis was to compare the long-term survival, mortality, morbidity and the operation-related events in patients with periampullary and pancreatic carcinoma undergoing pylorus-preserving pancreaticoduodenectomy (PPPD) and pylorus-resecting pancreaticoduodenectomy (PRPD).</p><p>Method</p><p>A systematic search of literature databases (Cochrane Library, PubMed, EMBASE and Web of Science) was performed to identify studies. Outcome measures comparing PPPD versus PRPD for periampullary and pancreatic carcinoma were long-term survival, mortality, morbidity (overall morbidity, delayed gastric emptying [DGE], pancreatic fistula, wound infection, postoperative bleeding, biliary leakage, ascites and gastroenterostomy leakage) and operation related events (hospital stays, operating time, intraoperative blood loss and red blood cell transfusions).</p><p>Results</p><p>Eight randomized controlled trials (RCTs) including 622 patients were identified and included in the analysis. Among these patients, it revealed no difference in long-term survival between the PPPD and PRPD groups (HR = 0.23, p = 0.11). There was a lower rate of DGE (RR = 2.35, p = 0.04, 95% CI, 1.06–5.21) with PRPD. Mortality, overall morbidity, pancreatic fistula, wound infection, postoperative bleeding, biliary leakage, ascites and gastroenterostomy leakage were not significantly different between the groups. PPPDs were performed more quickly than PRPDs (WMD = 53.25 minutes, p = 0.01, 95% CI, 12.53–93.97); and there was less estimated intraoperative blood loss (WMD = 365.21 ml, p = 0.006, 95% CI, 102.71–627.71) and fewer red blood cell transfusions (WMD = 0.29 U, p = 0.003, 95% CI, 0.10–0.48) in patients undergoing PPPD. The hospital stays showed no significant difference.</p><p>Conclusions</p><p>PPPD had advantages over PRPD in operating time, intraoperative blood loss and red blood cell transfusions, but had a significantly higher rate of DGE for periampullary and pancreatic carcinoma. PPPD and PRPD had comparable mortality and morbidity including pancreatic fistulas, wound infections, postoperative bleeding, biliary leakage, ascites and gastroenterostomy leakage. Our conclusions were limited by the available data. Further evaluations of high-quality RCTs are needed.</p></div

Forest plot of long-term survival.

<p>The 95% confidence interval (CI) for the hazard ratio for each study is represented by a horizontal line and the point estimate is represented by a square. The size of the square corresponds to the weight of the study in the meta-analysis. Pooled treatment effect is shown as a diamond that spans the 95% CI. Data for a fix-effects model are shown as there was low statistical heterogeneity (I² = 31%). df  =  degrees of freedom; IV  =  Inverse Variance; I² =  percentage of the total variation across studies due to heterogeneity; Z =  test of overall treatment effect.</p

Forest plot of red blood cell transfusion.

<p>The 95% confidence interval (CI) for the hazard ratio for each study is represented by a horizontal line and the point estimate is represented by a square. The size of the square corresponds to the weight of the study in the meta-analysis. The 95% CI for pooled estimates is represented by a diamond. Data for a fix-effects model is shown as there was no statistical heterogeneity (I² = 0%). df  =  degrees of freedom; I² =  percentage of the total variation across studies due to heterogeneity; IV =  Inverse Variance; Z =  test of overall treatment effect.</p

A flow chart showing the progress of trials through the review.

<p>A flow chart showing the progress of trials through the review.</p

A wireless battery-free eye modulation patch for high myopia therapy

The proper axial length of the eye is crucial for achieving emmetropia. In this study, we present a wireless battery-free eye modulation patch designed to correct high myopia and prevent relapse. The patch consists of piezoelectric transducers, an electrochemical micro-actuator, a drug microneedle array, μ-LEDs, a flexible circuit, and biocompatible encapsulation. The system can be wirelessly powered and controlled using external ultrasound. The electrochemical micro-actuator plays a key role in precisely shortening the axial length by driving the posterior sclera inward. This ensures accurate scene imaging on the retina for myopia eye. The drug microneedle array delivers riboflavin to the posterior sclera, and μ-LEDs' blue light induces collagen cross-linking, reinforcing sclera strength. In vivo experiments demonstrate that the patch successfully reduces the rabbit eye's axial length by ~1217 μm and increases sclera strength by 387%. The system operates effectively within the body without the need for batteries. Here, we show that the patch offers a promising avenue for clinically treating high myopia

Egger's test and Begg's test of outcomes included in the meta-analysis.

<p>Abbreviations and notes: NA, data not available.</p

Forest plot of intraoperative blood loss.

<p>The 95% confidence interval (CI) for the hazard ratio for each study is represented by a horizontal line and the point estimate is represented by a square. The size of the square corresponds to the weight of the study in the meta-analysis. The 95% CI for pooled estimates is represented by a diamond. Data for a random-effects model is shown as there was high statistical heterogeneity (I² = 81%). df  =  degrees of freedom; I² =  percentage of the total variation across studies due to heterogeneity; IV =  Inverse Variance; Z =  test of overall treatment effect.</p