Cardiac resynchronization therapy in inotrope-dependent heart failure: a meta-analysis.

AIMS: The viability of cardiac resynchronization therapy (CRT) in inotrope-dependent heart failure (HF) has been a matter of debate. METHODS AND RESULTS: We searched Medline, EMBASE, Scopus, and the Cochrane Library until 31 December 2022. Studies were included if (i) HF patients required inotropic support at CRT implantation; (ii) patients were ≥18 years old; and (iii) they provided a clear definition of 'inotrope dependence' or 'inability to wean'. A meta-analysis was performed in R (Version 3.5.1). Nineteen studies comprising 386 inotrope-dependent HF patients who received CRT (mean age 64.4 years, 76.9% male) were included. A large majority survived until discharge at 91.1% [95% confidence interval (CI): 81.2% to 97.6%], 89.3% were weaned off inotropes (95% CI: 77.6% to 97.0%), and mean discharge time post-CRT was 7.8 days (95% CI: 3.9 to 11.7). After 1 year of follow-up, 69.7% survived (95% CI: 58.4% to 79.8%). During follow-up, the mean number of HF hospitalizations was reduced by 1.87 (95% CI: 1.04 to 2.70, P < 0.00001). Post-CRT mean QRS duration was reduced by 29.0 ms (95% CI: -41.3 to 16.7, P < 0.00001), and mean left ventricular ejection fraction increased by 4.8% (95% CI: 3.1% to 6.6%, P < 0.00001). The mean New York Heart Association (NYHA) class post-CRT was 2.7 (95% CI: 2.5 to 3.0), with a pronounced reduction of individuals in NYHA IV (risk ratio = 0.27, 95% CI: 0.18 to 0.41, P < 0.00001). On univariate analysis, there was a higher prevalence of males (85.7% vs. 40%), a history of left bundle branch block (71.4% vs. 30%), and more pronounced left ventricular end-diastolic dilation (274.3 ± 7.2 vs. 225.9 ± 6.1 mL). CONCLUSIONS: CRT appears to be a viable option for inotrope-dependent HF, with some of these patients seeming more likely to respond.

On the Formation of Black Silicon Features by Plasma-Less Etching of Silicon in Molecular Fluorine Gas.

In this paper, we study the plasma-less etching of crystalline silicon (c-Si) by F2/N2 gas mixture at moderately elevated temperatures. The etching is performed in an inline etching tool, which is specifically developed to lower costs for products needing a high volume manufacturing etching platform such as silicon photovoltaics. Specifically, the current study focuses on developing an effective front-side texturing process on Si(100) wafers. Statistical variation of the tool parameters is performed to achieve high etching rates and low surface reflection of the textured silicon surface. It is observed that the rate and anisotropy of the etching process are strongly defined by the interaction effects between process parameters such as substrate temperature, F2 concentration, and process duration. The etching forms features of sub-micron dimensions on c-Si surface. By maintaining the anisotropic nature of etching, weighted surface reflection (Rw) as low as Rw < 2% in Si(100) is achievable. The lowering of Rw is mainly due to the formation of deep, density grade nanostructures, so-called black silicon, with lateral dimensions that are smaller to the major wavelength ranges of interest in silicon photovoltaics.

Toward real-time remote processing of laparoscopic video.

Laparoscopic surgery is a minimally invasive surgical technique where surgeons insert a small video camera into the patient's body to visualize internal organs and use small tools to perform surgical procedures. However, the benefit of small incisions has a drawback of limited visualization of subsurface tissues, which can lead to navigational challenges in the delivering of therapy. Image-guided surgery uses the images to map subsurface structures and can reduce the limitations of laparoscopic surgery. One particular laparoscopic camera system of interest is the vision system of the daVinci-Si robotic surgical system (Intuitive Surgical, Sunnyvale, California). The video streams generate approximately 360 MB of data per second, demonstrating a trend toward increased data sizes in medicine, primarily due to higher-resolution video cameras and imaging equipment. Processing this data on a bedside PC has become challenging and a high-performance computing (HPC) environment may not always be available at the point of care. To process this data on remote HPC clusters at the typical 30 frames per second (fps) rate, it is required that each 11.9 MB video frame be processed by a server and returned within 1/30th of a second. The ability to acquire, process, and visualize data in real time is essential for the performance of complex tasks as well as minimizing risk to the patient. As a result, utilizing high-speed networks to access computing clusters will lead to real-time medical image processing and improve surgical experiences by providing real-time augmented laparoscopic data. We have performed image processing algorithms on a high-definition head phantom video (1920 × 1080 pixels) and transferred the video using a message passing interface. The total transfer time is around 53 ms or 19 fps. We will optimize and parallelize these algorithms to reduce the total time to 30 ms.

The transcriptomic responses of the eastern oyster, Crassostrea virginica, to environmental conditions.

Understanding the mechanisms by which organisms adapt to environmental conditions is a fundamental question for ecology and evolution. In this study, we evaluate changes in gene expression of a marine mollusc, the eastern oyster Crassostrea virginica, associated with the physico-chemical conditions and the levels of metals and other contaminants in their environment. The results indicate that transcript signatures can effectively disentangle the complex interactive gene expression responses to the environment and are also capable of disentangling the complex dynamic effects of environmental factors on gene expression. In this context, the mapping of environment to gene and gene to environment is reciprocal and mutually reinforcing. In general, the response of transcripts to the environment is driven by major factors known to affect oyster physiology such as temperature, pH, salinity, and dissolved oxygen, with pollutant levels playing a relatively small role, at least within the range of concentrations found in the studied oyster habitats. Further, the two environmental factors that dominate these effects (temperature and pH) interact in a dynamic and nonlinear fashion to impact gene expression. Transcriptomic data obtained in our study provide insights into the mechanisms of physiological responses to temperature and pH in oysters that are consistent with the known effects of these factors on physiological functions of ectotherms and indicate important linkages between transcriptomics and physiological outcomes. Should these linkages hold in further studies and in other organisms, they may provide a novel integrated approach for assessing the impacts of climate change, ocean acidification and anthropogenic contaminants on aquatic organisms via relatively inexpensive microarray platforms.

Effect of planning margin on dosimetric quality in 131Cs permanent prostate brachytherapy.

PURPOSE: To investigate the dosimetric effect of planning margin in (131)Cs prostate seed implants. METHODS AND MATERIALS: The transrectal ultrasonography images are obtained intraoperatively in 5-mm steps from base to apex. The prostate is contoured as clinical target volume (CTV). The CTV is enlarged with 3mm expansion except the posterior. The CTV and planning target volume (PTV) are then used as planning target for treatment planning, respectively. Dose calculations are performed using VariSeed treatment planning system using AAPM TG-43 formalism. The total activity implanted, target coverage (the percent of the prostate volume covered by the prescription dose, V(100); the dose that covers 90% of the prostate volume, D(90)) for CTV and PTV, dose inhomogeneity (the percentage volume of the prostate receiving 150% of the prescription dose [V(150)]), and the critical organ dose (the dose that covers 10% of the urethra volume [UD(10)] for urethra and the dose that covers 50% of the rectum volume [RD(50)] for rectum) are compared. RESULTS: When CTV is used as target for planning, compared with PTV as planning target, the total activity implanted is decreased by 5.6%. Integral dose is thus lower by 5.6%. Coverage for CTV (CTV(100)) is increased by 0.3%. Coverage for PTV (PTV(100)) is lower by 2.1%. CTV(150) is increased by 13.6%. PTV(150) is higher by 2.5% with a standard deviation of 10.2%. Rectum dose (RD(50)) is lower by 4.5%. Urethra dose (UD(10)) is higher by 10.0%. CONCLUSION: It is shown that the planning margin has minimal effect on dosimetric quality because of (131)Cs's gradual dose fall-off. Thus, it is possible to reduce or even eliminate planning margin using (131)Cs. The modest benefits in reducing the planning margin, such as lower total activity (lower integral dose), dose reduction to surrounding healthy tissues and reduced likelihood of seeds migration, can be achieved while adequate coverage is maintained.

Physical derivation of nomograms in permanent prostate brachytherapy.

PURPOSE: To demonstrate the physical origin of nomograms in permanent prostate brachytherapy, by using the correlation between fractional integral target dose (FITD) and target volume. METHODS AND MATERIALS: The integral dose (ID) E delivered by unit activity is given by the integration of 4pi r(2)D(r)/r(2)dr x 1.44T(1/2) using the point source model from AAPM TG43. If A is the total activity implanted, then total ID will be AxE. Integral target dose are obtained by multiplying the prostate volume V with mean dose D(mean) by definition, assuming prostate gland has a unity density. The FITD the target receives is defined as FITD=D(mean)V/AE by energy conservation in the target volume. From this equation, the total activity needed to achieve given dose for a target of volume V is obtained. Results are compared with existing nomograms for (125)I and (103)Pd, and available clinical data for (131)Cs. RESULTS: Agreement within 10.0% for (125)I and (103)Pd compared with existing nomograms for gland sizes from 18 to 80 cc is observed. For (131)Cs, the agreement is within 8.0% compared with available clinical data. CONCLUSIONS: It is shown that the correlation between the FITD and target volume can be used to obtain the total activity needed to achieve prescribed dose. This correlation is inherent rather than empirical. It suggests that the correlation between fraction of energy deposition in target and target volume is the underlying physical origin for nomograms used in permanent prostate brachytherapy.