bluuebunny/crossref_metadata_2025_split huggingface dataset:
Transition-Metal-Catalyzed Enantioselective α-Arylation of Carbonyl Compounds to Give Tertiary Stereocenters
Authors: Orlandi Manuel , Escudero-Casao Margarita , Licini Giulia 
Published: July 2021

AbstractEnantioenriched α-aryl carbonyl compounds are ubiquitous in natural products and biologically active compounds. Their synthesis has been explored over the last few decades and several methods now exist that allow for the enantioselective formation of a C(sp3)-C(sp2) bond in the α-position to a carbonyl group. However, although the formation of quaternary stereocenters has been fairly well established, the enantioselective formation of tertiary stereocenters proved more challenging due to facile product post-reaction racemization. In this short review, we summarize the methods reported to date for the asymmetric α-arylation of enolates and analogues that rely on transition-metal catalysis.1	Introduction2	Nucleophile Pre-activation3	Activation via Aminocatalysis4	Formation of Constrained Stereocenters5	Concluding Remarks
Catalytic, Enantioselective Diamination of Alkenes
Authors: Denmark Scott E. , Tao Zhong-Lin 
Published: July 2021

AbstractEnantioselective diamination of alkenes represents one of the most straightforward methods to access enantioenriched, vicinal diamines, which are not only frequently encountered in biologically active compounds, but also have broad applications in asymmetric synthesis. Although the analogous dihydroxylation of olefins is well-established, the development of enantioselective olefin diamination lags far behind. Nevertheless, several successful methods have been developed that operate by different reaction mechanisms, including a cycloaddition pathway, a two-electron redox pathway, and a radical pathway. This short review summarizes recent advances and identifies limitations, with the aim of inspiring further developments in this area.1	Introduction2	Cycloaddition Pathway3	Two-Electron Redox Pathway3.1	Pd(0)/Pd(II) Diamination3.2	Pd(II)/Pd(IV) Diamination3.3	I(I)/I(III) Diamination3.4	Se(II)/Se(IV) Diamination4	One-Electron Radical Pathway4.1	Cu-Catalyzed Diamination4.2	Fe-Catalyzed Diamination5	Summary and Outlook
SARS-CoV-2 Infection and Placental Pathology
Authors: Leal Caio Ribeiro Vieira , Maciel Rayra Amana Macêdo , Corrêa Júnior Mário Dias 
Published: July 2021

AbstractPlacental pathophysiology in SARS-CoV-2 infection can help researchers understand more about the infection and its impact on the maternal/neonatal outcomes. This brief review provides an overview about some aspects of the placental pathology in SARS-CoV-2 infection. In total, 11 papers were included. The current literature suggests that there are no specific histopathological characteristics in the placenta related to SARS-CoV-2 infection, but placentas from infected women are more likely to show findings of maternal and/or fetal malperfusion. The most common findings in placentas from infected women were fibrin deposition and intense recruitment of inflammatory infiltrates. The transplacental transmission of this virus is unlikely to occur, probably due to low expression of the receptor for SARS-CoV-2 in placental cell types. Further studies are needed to improve our knowledge about the interaction between the virus and the mother-fetus dyad and the impact on maternal and neonatal/fetal outcomes.
Predictive Outcome Modeling of Preoperative Clinical Symptoms and Electrodiagnostic Data in Tarsal Tunnel Surgery
Authors: Seidel Geoffrey K. , Jamal Salma Al , Weidert Eric , Carington Frederick , Andary Michael T. , Millis Scott R. , Loder Brian G. 
Published: July 2021

Abstract
Background The relationship between tarsal tunnel syndrome (TTS), electrodiagnostic (Edx) findings, and surgical outcome is unknown. Analysis of TTS surgical release outcome patient satisfaction and comparison to Edx nerve conduction studies (NCSs) is important to improve outcome prediction when deciding who would benefit from TTS release.
Methods Retrospective study of 90 patients over 7 years that had tarsal tunnel (TT) release surgery with outcome rating and preoperative tibial NCS. Overall, 64 patients met study inclusion criteria with enough NCS data to be classified into one of the following three groups: (1) probable TTS, (2) peripheral polyneuropathy, or (3) normal. Most patients had preoperative clinical provocative testing including diagnostic tibial nerve injection, tibial Phalen's sign, and/or Tinel's sign and complaints of plantar tibial neuropathic symptoms. Outcome measure was percentage of patient improvement report at surgical follow-up visit.
Results Patient-reported improvement was 92% in the probable TTS group (n = 41) and 77% of the non-TTS group (n = 23). Multivariate modeling revealed that three out of eight variables predicted improvement from surgical release, NCS consistent with TTS (p = 0.04), neuropathic symptoms (p = 0.045), and absent Phalen's test (p = 0.001). The R
2 was 0.21 which is a robust result for this outcome measurement process.
Conclusion The best predictors of improvement in patients with TTS release were found in patients that had preoperative Edx evidence of tibial neuropathy in the TT and tibial nerve plantar symptoms. Determining what factors predict surgical outcome will require prospective evaluation and evaluation of patients with other nonsurgical modalities.
Dry Arthroscopy Distal Radioulnar Joint and Foveal Insertion: Surgical Technique
Authors: Ecker Jeff , Andrijich Courtney 
Published: July 2021

Abstract
Background Arthroscopy of the distal radioulnar joint is considered to be difficult to perform. At this time the integrity of the foveal insertion is indirectly evaluated with a hook test. If a hook test is positive it is inferred that the foveal insertion is torn or incompetent.
Description of Technique The ideal way to evaluate the foveal insertion is by direct visualization and probing. In order to do this, arthroscopic examination of the distal radioulnar joint and foveal insertion is required. The article describes how to reliably perform “dry” arthroscopy of the distal radioulnar joint and foveal insertion using a 1.9 mm arthroscope to accurately assess the triangular fibrocartilage complex and foveal insertion.
Patient and Methods A total of 169 dry DRUJ arthroscopies were performed by the primary author between January 2018 and February 2021.
Results Using this technique, the foveal insertion was successfully visualized in 168 cases (99%).
Conclusion Dry arthroscopy of the DRUJ is a reliable technique to evaluate the integrity of the foveal insertion.
Oxidant and Antioxidant Balance in Children with Community-Acquired Pneumonia
Authors: Aykac Kubra , Ozsurekci Yasemin , Tanir Basaranoglu Sevgen , Avcioglu Gamze , Karadag Oncel Eda , Erel Ozcan , Cengiz Ali Bulent , Karahan Sevilay , Ceyhan Mehmet 
Published: July 2021

Abstract
Objective The balance between oxidant and antioxidant defense mechanisms is crucial. In this article, we aimed to evaluate the role of this balance in community-acquired pneumonia (CAP) in children.
Methods We analyzed serum oxidant and antioxidant stress parameters according to the clinical and demographic data of children with CAP and compared them with healthy controls. Serum total antioxidant status (TAS) and total oxidant status (TOS) were evaluated and compared between the groups, along with levels of ischemia-modified albumin (IMA), antioxidant enzymes, nonenzymatic antioxidant factors, and plasma thiol.
Results Of 160 children evaluated, 106 had CAP (54 outpatients and 52 inpatients), and the other 54 were healthy (control group). Total thiol and native thiol levels were significantly lower in the inpatient group compared with the outpatient group (p = 0.004 and p = 0.005, respectively). Serum IMA differed significantly among the groups (p = 0.001), with inpatients showing the highest level. A positive correlation was found between serum IMA and C-reactive protein levels in patients with pneumonia (r = 0.351; p = 0.001).
Conclusion Parameters that provide information about antioxidant capacity may be useful in the diagnosis and prognosis of pneumonia. Our results suggest that plasma thiol levels and IMA may be good candidate biomarkers to predict hospitalization for CAP in children.
Radiation Exposure in the Neonatal Intensive Care Unit in Newborns and Staff
Authors: Cakir Salih Cagri , Dorum Bayram Ali , Koksal Nilgun , Ozkan Hilal , Yazici Zeynep , Parlak Mufit , Gulleroglu Nadide Basak 
Published: July 2021

Objective Portable X-rays remain one of the most frequently used diagnostic procedures in neonatal intensive care units (NICU). Premature infants are more sensitive to radiation-induced harmful effects. Dangers from diagnostic radiation can occur with stochastic effects. We aimed to determine the radiation exposure in premature infants and staff and determine the scattering during X-ray examinations in the NICU.
Study Design In this prospective study, dosimeters were placed on premature infants who were ≤1,250 g at birth and ≤30 weeks of gestational age who stayed in the NICU for at least 4 weeks. The doses were measured at each X-ray examination during their stay. The measurements of the nurses and the doctors in the NICU were also performed with dosimeters over the 1-month period. Other dosimeters were placed in certain areas outside the incubator and the results were obtained after 1 month.
Results The mean radiation exposure of the 10 premature infants, monitored with dosimeters, was 3.65 ± 2.44 mGy. The mean skin dose of the six staff was 0.087 ± 0.0998 mSV. The mean scattered dose was 67.9 ± 26.5 µGy.
Conclusion Relatively high exposures were observed in 90% of the patients and two staff. The radiation exposure levels of premature infants and staff may need to be monitored continuously.
Key Points
Indian College of Radiology and Imaging Evidence-Based Guidelines for Percutaneous Image-Guided Biliary Procedures
Authors: Madhusudhan Kumble Seetharama , Jineesh Valakkada , Keshava Shyamkumar Nidugala 
Published: July 2021

AbstractPercutaneous biliary interventions are among the commonly performed nonvascular radiological interventions. Most common of these interventions is the percutaneous transhepatic biliary drainage for malignant biliary obstruction. Other biliary procedures performed include percutaneous cholecystostomy, biliary stenting, drainage for bile leaks, and various procedures like balloon dilatation, stenting, and large-bore catheter drainage for bilioenteric or post-transplant anastomotic strictures. Although these procedures are being performed for ages, no standard guidelines have been formulated. This article attempts at preparing guidelines for performing various percutaneous image-guided biliary procedures along with discussion on the published evidence in this field.
In Achilles Tendon Disorders, Will Sonoelastography Add to Grey-Scale Ultrasound? Using MRI as Gold Standard
Authors: Kandil Nour Mohamed , Abdelkarim Maha Ahmed , Abdelwahab Nagui Mohamed , Hashem Aya Mohamed 
Published: July 2021

Abstract
Background The aim of this study was to verify the findings of color-coded sonoelastography in Achilles tendon disorders against ultrasonographic and MR imaging findings, describing the elastographic patterns and correlating their diagnostic ability to magnetic resonance imaging (MRI) as a gold standard.
Results Our study showed that sonoelastography appeared to be highly sensitive to ultrasonographically detected changes, with 100% sensitivity, 16.6% specificity, 73% positive predictive value, and 100% negative predictive value, making it a good negative test to exclude suspected tendinopathy in equivocal cases. MRI examination was used as a gold standard. Elastographic grades showed moderate agreement to those of MRI (κ = 0.44, p < 0.001), while elastography had overall sensitivity of 87.5%, 100% specificity, and 90% accuracy in differentiating normal and pathological tendons.
Conclusion We concluded that sonoelastography is a sensitive method in the diagnosis of Achilles tendon pathologies detected by ultrasound examination and it can be well correlated to MRI with high specificity for pathological tendons.
Role of Imaging in a Case of Toxoplasmosis Presenting as Generalized Lymphadenopathy
Authors: Pratap Thara , Jalal Muhammed Jasim Abdul , K. Vishnu A. , Raja Senthil 
Published: July 2021

AbstractToxoplasmosis is caused by Toxoplasma gondii an obligate protozoan intracellular parasite. The disease has variable prevalence globally and is usually asymptomatic. Pregnant and immunocompromised people are at risk of getting infected. Enlarged lymph nodes are the most frequently observed clinical form of Toxoplasma in humans, mostly affecting posterior cervical nodes. Other organs usually affected are the brain and eyes. We present a case of toxoplasmosis with generalized lymphadenopathy mimicking metastasis in a lady with a previous history of operated pancreatic neoplasm.
Indian College of Radiology and Imaging (ICRI) Consensus Guidelines for the Early Management of Patients with Acute Ischemic Stroke: Imaging and Intervention
Authors: Londhe Shrikant R , GG Sharath Kumar , Keshava Shyamkumar N. , Mohan Chander 
Published: July 2021

AbstractThe medical science has witnessed significant change in the management of acute stroke patients as a result of recent advances in the field of stroke imaging and endovascular mechanical thrombectomy in addition to intravenous thrombolysis and optimization of stroke services in balance with available resources. Despite initial negative trials, we witnessed the publication of five multicenter randomized clinical trials showing superiority of the endovascular approach over standard medical management in patients with large vessel occlusion. The aim of this study is to provide comprehensive set of evidence-based recommendations regarding imaging and endovascular interventions in acute ischemic stroke patients.
TIPIC—A Newly Recognized Syndrome: Multimodality Imaging of a Rare Clinicoradiological Entity
Authors: Modi Tanvi , Verma Mitusha , Ahuja Gauri , Kamat Neemish , Patkar Deepak P. 
Published: July 2021

AbstractCarotidynia is a controversial clinicopathological entity vastly described in Western literature as neck pain in the region of carotid bifurcation secondary to an underlying inflammatory etiology. Radiologically, this appears as perivascular inflammation and has recently been designated as transient perivascular inflammation of the carotid artery (TIPIC) syndrome. The authors of this report discuss the multimodality imaging features of a rare case of this disease in our country to familiarize radiologists with the imaging findings and to encourage the inclusion of TIPIC syndrome as a differential diagnosis for focal neck pain.
Diagnostic Utility of Mean Peak Systolic Velocity of Superior Thyroid Artery in Differentiating Graves’ Disease from Thyroiditis
Authors: Sarangi Pradosh K. , Parida Sasmita , Mangaraj Swayamsidha , Mohanty Binoy K. , Mohanty Jayashree , Swain Basanta M. 
Published: July 2021

Abstract
Background Differentiating Graves’ disease from thyroiditis can be at times clinically challenging. The gold standard test (thyroid nuclear imaging scan) is expensive, not routinely available, and has radiation exposure. Color Doppler ultrasonography of thyroid represents a suitable alternate which can be used for differentiating these conditions by studying thyroid blood flow parameters.
Aim We aimed to investigate the use of thyroid blood flow parameters’ assessment of the superior thyroid artery (STA) and common carotid artery (CCA) with color Doppler ultrasonography for differentiating Graves’ disease from thyroiditis.
Materials and Methods This is a cross-sectional study on 111 patients with newly diagnosed thyrotoxicosis (82 with Graves’ disease and 29 with thyroiditis) and 45 years of age and sex-matched healthy controls. All patients underwent detailed clinical and necessary investigations. Color Doppler ultrasonography of the thyroid gland and spectral flow analysis of both superior thyroid arteries was done using standard protocol. Sensitivity and specificity for mean peak systolic velocity of STA (STA-PSV) cut-offs were calculated using receiver operating characteristic curves.
Results Patients with Graves’ disease have significantly higher free tri-iodothyronine (FT3) levels, free thyroxine (FT4) levels, antithyroid stimulating hormone receptor antibody (TRAb) levels, and thyroid volume as compared with those with thyroiditis. The mean STA-PSV of patients with Graves’ disease was significantly higher than thyroiditis and control group. Mean STA-PSV greater than 54.3 cm/s had 82.9% sensitivity and 86.2% specificity in diagnosing Graves’ disease. Mean PSV-STA/PSV-CCA ratio of 0.40 was 80.5% sensitive and 86.2% specific for Graves’ disease.
Conclusion Mean STA-PSV has high sensitivity and specificity in differentiating Graves’ disease from thyroiditis and can be used routinely in clinical practice as a cheap and invaluable diagnostic tool.
Loes Score: Clinical and Radiological Profile of 22 Patients of X-Linked Adrenoleukodystrophy: Case Series from a Single Center
Authors: Kumar Somesh , Sait Haseena , Polipalli Sunil K. , Pradhan Gaurav S. , Pruthi Sumit , Kapoor Seema 
Published: July 2021

Abstract
Introduction X-linked adrenoleukodystrophy (X-ALD) is a devastating disease with a wide spectrum of presentation ranging from asymptomatic to a rapidly progressive childhood cerebral form. The gene responsible for adrenoleukodystrophy is ABCD1 gene, required for β oxidation of fatty acids in various tissues. While biochemical and molecular techniques are available to confirm the diagnosis, brain magnetic resonance imaging (MRI) utilizing Loes score has been used for both prognosis and timely direction of hematopoietic stem cell therapy.
Materials and Methods During the study period of 2016 to 2020, 22 individuals including 19 individuals with features suggestive of X-ALD and 3 asymptomatic siblings were evaluated from a single center in North India. After biochemical and molecular confirmation of the disease, detailed clinical and radiological findings using MRI brain were documented. A radiological scoring pattern proposed by Loes was employed to identify the severity of the disorder.
Results The most common clinical presentations were visual difficulty and muscular weakness (58%). All symptomatic individuals had classic neuroimaging findings in the form of hyperintensities involving the parieto-occipital area and splenium of corpus callosum. Severe involvement in the form of global atrophy was observed in 52.6% of individuals. Asymptomatic siblings also showed neurological involvement based on MRI with highest Loes score of 9 in one individual.
Conclusion This case series describes the clinical and radiological profile and employment of Loes score in individuals with X-ALD. Early identification of asymptomatic individuals by neuroimaging and use of Loes severity score for monitoring and disease progression will help in making therapeutic decisions in a timely manner.
Modern methods of detecting single photons and their application in quantum communications
Authors: Koziy A.A. , Losev A.V. , Zavodilenko V.V. , Kurochkin Yu.V. , Gorbatsevich A.A. 
Published: July 2021

AbstractWe consider main methods for detecting single photons used in quantum communications, including the quantum key distribution (QKD) technology. Two most promising single photon detectors (SPDs) based on superconducting nanowires and on a single-photon avalanche diode are described. The most effective SPD designs are presented and their advantages and disadvantages are analysed from the point of view of the possibility of their use in QKD devices. The results of the work of various scientific groups conducting research on QKD are discussed, which makes it possible to trace the trends in the global technological development of this industry over the past five years.
Passive method of laser radiation smoothing using spectral dispersion
Authors: Sizmin D.V. , Pugacheva V.N. , Starodubtsev K.V. , Dushina L.A. , Gorchakov O.I. , Derkach V.N. , Voronich I.N. 
Published: July 2021

AbstractA new version of the method for spatiotemporal smoothing of laser radiation using spectral dispersion is proposed, which does not require the use of high-frequency phase modulators, i.e. a method based on the use of a broadband master oscillator. An experimental study of this method has been conducted on the Luch laser facility.
Principle of measuring the electron population of a quantum dot using a single-photon transistor based on an array of quantum dots
Authors: Tsukanov A.V. 
Published: July 2021

AbstractThe scheme of a single-photon transistor formed by an array of semiconductor single-electron quantum dots in an optical resonator is considered. The spectral response of such a transistor depends on the Coulomb interaction of the electrons of the array with the electron at the measured quantum dot. An approximate analytical expression is obtained for the response function of a transistor with an arbitrary number of quantum dots. Using a one-dimensional array (chain) as an example, the dependences of the transistor response on the chain period, on the distance to the measured quantum dot, and on the degree of compensation for Coulomb effects are analysed. It is shown that the electron – photon dynamics of the transistor is substantially affected by the Förster effect, the suppression of which by alternating quantum dots with different symmetry of the excited state significantly increases the measurement accuracy.
Measurements of the absolute intensities of spectral lines of Kr, Ar, and O ions in the wavelength range of 10 – 18 nm under pulsed laser excitation
Authors: Vodop’yanov A.V. , Garakhin S.A. , Zabrodin I.G. , Zuev S.Yu. , Lopatin A.Ya. , Nechay A.N. , Pestov A.E. , Perekalov A.A. , Pleshkov R.S. , Polkovnikov V.N. , Salashchenko N.N. , Smertin R.M. , Ulasevich B.A. , Chkhalo N.I. 
Published: July 2021

AbstractWe have measured the absolute intensities of the spectral lines of Kr, Ar, and O ions (CO2gas), which are of interest for reflectometry, microscopy, and lithography in the wavelength range of 10 – 18 nm. We have used pulsed excitation by an Nd : YAG laser with an output wavelengthλ= 1064 nm, a pulse energy of 0.8 J, a pulse duration of 5.2 ns and a pulse repetition rate of 10 Hz. The targets are formed during gas outflow through a pulsed supersonic conical nozzle for an inlet gas pressure of 3.5 bar. A spectrometer based on X-ray multilayer mirrors and its calibration procedure are described in detail. The absolute intensities of the spectral lines of Kr IX (λ= 11.5 nm; number of photons:N= 9.3 × 1012photons pulse−1), Ar VIII (λ= 13.84 nm,N= 3 × 1012photons pulse−1), and O VI (λ= 12.98 nm,N= 5.17 × 1012photons pulse−1). The results are compared with the data obtained for Xe ions under the same experimental conditions at the same wavelengths.
Concept of a miniature photonic spatial switch based on an off-axis zone plate
Authors: Geints Yu.E. , Minin O.V. , Minin I.V. 
Published: July 2021

Abstract
A new concept of an all-optical wavelength-selective two-channel switch based on the photonic hook effect without the use of micromechanical devices or nonlinear materials is proposed. A prototype of such a device based on an off-axis Fresnel zone plate is considered and its main parameters are discussed. Due to the unique property of the photonic hook to change its curvature with respect to the irradiation wavelength λ, this switch is a promising candidate for the implementation of optical switching in modern optoelectronics and miniature ‘on-a-chip’ devices. Numerical simulation shows that the optical isolation of switched channels for a switch with linear dimensions of about (6λ)3 based on an off-axis zone plate can reach 18 – 20 dB during operation in the wavelength range of 1.5 – 1.9 μm.