Single-Beam Coherent Raman Spectroscopy and Microscopy via Spectral Notch Shaping

Raman spectroscopy is one of the key techniques in the study of vibrational modes and molecular structures. In Coherent Anti-Stokes Raman Scattering (CARS) spectroscopy, a molecular vibrational spectrum is resolved via the third-order nonlinear interaction of pump, Stokes and probe photons, typically using a complex experimental setup with multiple beams and laser sources. Although CARS has become a widespread technique for label-free chemical imaging and detection of contaminants, its multi-source, multi-beam experimental implementation is challenging. In this work we present a simple and easily implementable scheme for performing single-beam CARS spectroscopy and microscopy using a single femtosecond pulse, shaped by a tunable narrowband notch filter. As a substitute for multiple sources, the single broadband pulse simultaneously provides the pump, Stokes and probe photons, exciting a broad band of vibrational levels. High spectroscopic resolution is obtained by utilizing a tunable spectral notch, shaped with a resonant photonic crystal slab filter, as a narrowband, time-delayed probe. Using this scheme the entire vibrational spectrum can be resolved in a single-shot multiplexed measurement, circumventing the need for a multi-source configuration or a complex pulse-shaping apparatus. We demonstrate high-resolution single-beam micro-spectroscopy and vibrational imaging of various samples in the 300cm^{-1}-1000cm^{-1} spectral range

Focusing and Compression of Ultrashort Pulses through Scattering Media

Light scattering in inhomogeneous media induces wavefront distortions which pose an inherent limitation in many optical applications. Examples range from microscopy and nanosurgery to astronomy. In recent years, ongoing efforts have made the correction of spatial distortions possible by wavefront shaping techniques. However, when ultrashort pulses are employed scattering induces temporal distortions which hinder their use in nonlinear processes such as in multiphoton microscopy and quantum control experiments. Here we show that correction of both spatial and temporal distortions can be attained by manipulating only the spatial degrees of freedom of the incident wavefront. Moreover, by optimizing a nonlinear signal the refocused pulse can be shorter than the input pulse. We demonstrate focusing of 100fs pulses through a 1mm thick brain tissue, and 1000-fold enhancement of a localized two-photon fluorescence signal. Our results open up new possibilities for optical manipulation and nonlinear imaging in scattering media

Increased risk of severe clinical course of COVID-19 in carriers of HLA-C*04:01

Background: Since the beginning of the coronavirus disease 2019 (COVID-19) pandemic, there has been increasing urgency to identify pathophysiological characteristics leading to severe clinical course in patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Human leukocyte antigen alleles (HLA) have been suggested as potential genetic host factors that affect individual immune response to SARS-CoV-2. We sought to evaluate this hypothesis by conducting a multicenter study using HLA sequencing. Methods: We analyzed the association between COVID-19 severity and HLAs in 435 individuals from Germany (n = 135), Spain (n = 133), Switzerland (n = 20) and the United States (n = 147), who had been enrolled from March 2020 to August 2020. This study included patients older than 18 years, diagnosed with COVID19 and representing the full spectrum of the disease. Finally, we tested our results by meta-analysing data from prior genome-wide association studies (GWAS). Findings: We describe a potential association of HLA-C*04:01 with severe clinical course of COVID-19. Carriers of HLA-C*04:01 had twice the risk of intubation when infected with SARS-CoV-2 (risk ratio 1.5 [95% CI 1.1-2.1], odds ratio 3.5 [95% CI 1.9-6.6], adjusted p-value = 0.0074). These findings are based on data from four countries and corroborated by independent results from GWAS. Our findings are biologically plausible, as HLA-C*04:01 has fewer predicted bindings sites for relevant SARS-CoV-2 peptides compared to other HLA alleles. Interpretation: HLA-C*04:01 carrier state is associated with severe clinical course in SARS-CoV-2. Our findings suggest that HLA class I alleles have a relevant role in immune defense against SARS-CoV-2. Funding: Funded by Roche Sequencing Solutions, Inc

Contribution of histone sequence preferences to nucleosome organization: proposed definitions and methodology

We propose definitions and procedures for comparing nucleosome maps and discuss current agreement and disagreement on the effect of histone sequence preferences on nucleosome organization in vivo

Bilateral Maternal Pelvic Kidneys Presenting as a Tumor Previa: Sonographic Diagnosis and Obstetric Management

Renal ectopia occurs when the kidney fails to ascend normally to the retroperitoneal renal fossa. Bilateral cases have also been reported but are very rare. Pregnancy and labor with maternal renal ectopia provides a unique challenge to the obstetricians attempting to prevent damage to the kidneys during labor and allow safe delivery. We describe a case of congenital bilateral pelvic kidneys assessed and diagnosed by 3D sonography as “tumor previa” and managed accordingly

Successful antibiotic eradication of Streptococcus pneumoniae infection of a ventriculoatrial shunt

SummaryA case of Streptococcus pneumoniae meningitis in a possibly immune-compromised child with a ventriculoatrial shunt is described. The infection was successfully eradicated by treatment with intravenous ceftriaxone and rifampicin, without removal of the shunt

Surgical Treatment for Rectocele by Posterior Colporrhaphy Compared to Stapled Transanal Rectal Resection

Background: Rectocele is defined as a defect in the rectovaginal septum, causing symptoms like obstructed defecation syndrome (ODS), vaginal bulging, etc. Once the rectocele is larger than 3 cm and/or symptomatic, surgery should be considered. The surgical approach can be either transvaginal, transanal or transperineal. Two of the most common procedures in treating rectocele are posterior colporrhaphy (PC) and stapled trans anal rectal resection (STARR). The purpose of this study was to compare surgical outcomes of both procedures. Methods: This is a retrospective cohort study. Included were patients of the age of 18–85 years that underwent either STARR (n = 49 patients) or PC (n = 24 patients) procedures after a full clinical (defecography and physical exam before and after the surgery) and physiologic (a detailed questionnaire before and after the surgery) surveys. Symptoms of ODS before and after surgery were evaluated by questioners. Results: Preoperatively, the patients in the STARR group had significantly higher rates of ODS: straining (90.9% vs. 65.2%), incomplete evacuation (100% vs. 69.6%), hard stool (57.8% vs. 43.5%), sense of obstruction (76.1% vs. 56.5%), and use of digitation (64.4% vs. 47.8%), or laxatives (70% vs. 47.8%), p p p p p = 0.05) and sense of obstruction (17.6%, vs. 34.8%, p = 0.03), compared to the PC group. Among patients who underwent the STARR procedure, a decrease in rates of all symptoms was noted (straining 54.5%, incomplete evacuation 58.8%, hard stool 29.2%, sense of obstruction 58.5%, use of digitation 0.1%, and use of laxatives 31.5%). Both procedures are effective in reducing rectocele size (STARR- 1.9 ± 1 cm, PC- 3.1 ± 1). Conclusions: Both STARR and PC are effective in treating rectocele. It seems that the STARR procedure is superior to the PC procedure in treating symptoms of ODS

Comparison of sonographic fetal weight estimation formulas in patients with preterm premature rupture of membranes

Abstract Background Estimation of fetal weight (EFW) by ultrasound is useful in clinical decision-making. Numerous formulas for EFW have been published but have not been validated in pregnancies complicated by preterm premature rupture of membranes (PPROM). The purpose of this study is to compare the accuracy of EFW formulas in patients with PPROM, and to further evaluate the performance of the most commonly used formula - Hadlock IV. Methods A retrospective cohort study of women with singleton gestations and PPROM, admitted to a single tertiary center between 2005 and 2017 from 220/7–330/7 (n = 565). All women had an EFW within 14 days of delivery by standard biometry (biparietal diameter, head circumference, abdominal circumference and femur length). The accuracy of previously published 21 estimated EFW formulas was assessed by comparing the Pearson correlation with actual birth weight, and calculating the random error, systematic error, proportion of estimates within 10% of birth weight, and Euclidean distance. Results The mean gestational was 26.8 ± 2.4 weeks at admission, and 28.2 ± 2.6 weeks at delivery. Most formulas were strongly correlated with actual birth weight (r > 0.9 for 19/21 formulas). Mean systematic error was − 4.30% and mean random error was 14.5%. The highest performing formula, by the highest proportion of estimates and lowest Euclidean distance was Ott (1986), which uses abdominal and head circumferences, and femur length. However, there were minimal difference with all of the first 10 ranking formulas. The Pearson correlation coefficient for the Hadlock IV formula was strong at r = 0.935 (p < 0.001), with 319 (56.5%) of measurements falling within 10%, 408 (72.2%) within 15% and 455 (80.5%) within 20% of actual birth weight. This correlation was unaffected by gender (r = 0.936 for males, r = 0.932 for females, p < 0.001 for both) or by amniotic fluid level (r = 0.935 for mean vertical pocket < 2 cm, r = 0.943 for mean vertical pocket ≥2 cm, p < 0.001 for both). Conclusions In women with singleton gestation and PPROM, the Ott (1986) formula for EFW was the most accurate, yet all of the top ten ranking formulas performed quite well. The commonly used Hadlock IV performed quite similarly to Ott’s formula, and is acceptable to use in this specific setting