bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison of the Modified Alvarado Score and Ultrasonography for Diagnosing Acute Appendicitis
Authors: Keerthana S. , Vignaradj .
Published: January 2022

Background: Acute appendicitis can be diagnosed much accurately by using Modified Alvarado score and Ultrasound together in the clinical setting.

Objectives: Comparison of the diagnostic accuracy of Modified Alvarado score and Ultrasonographic findings in acute appendicitis.

Materials and Methods: A total of 200 patients of age group ranging from 4-65 years, both male and female, who visited the tertiary health care center with clinical features suggestive of acute appendicitis were randomly selected. Data from the patients regarding their Modified Alvarado score, ultrasonographic findings and histopathological reports were collected for the study. Statistical analysis was performed for the results of both Modified Alvarado score and Ultrasonographic findings in contrast to the pathology reports. 

Results: The study included 200 patients, with maximum incidence of acute appendicitis seen in males (70.5%) and among 21-30 age groups (40.5%). The sensitivity, specificity of Modified Alvarado Score was 89.47% and 73.33%, with Positive Predictive Value, Negative Predictive Value and diagnostic accuracy being 40%, 73.33% and 45% respectively. Ultrasonography revealed 89.58% sensitivity, 15.62 % specificity, Positive predictive value and NPV were 75.88% and 50%, and diagnostic accuracy was 72%. The negative appendectomies rates accounted to 15%.

Conclusion: It is advised that both Modified Alvarado score and Ultrasound can be used to together to diagnose acute appendicitis. This can be useful in decreasing the negative appendectomies and hence reduce the morbidity and mortality.
Tobacco use and Dependence in Adolescents: A Review
Authors: Algaows Faisal Suliman , Alidan Sara Gasem , Saad Hamad Mohammed Al , Al Nasser Mohammed Radhi , Alkhuwaytim Maryam Nasser , Madkhali Jalal Yahya Mohammed , Altamimi Saqr Muhammad , Al-Makki Talal Abdullah , Alothman Faisal Mohammed , Almutairi Futun Awadah M. , Alhawsawi Ameera Ahmad , Alotaibi Rahaf Abdulrahman , Alharbi Hamed Hamad B. , Shook Amani Hassan
Published: January 2022

Despite rising acknowledgement of the onset of tobacco smoking in children and adolescents, foundational understanding about many elements of early-life smoking behavior, as well as statistics to advocate for specific treatment approaches among children and adolescents, is inadequate. Nicotine addiction and withdrawal have been linked to continued cigarette use and difficulty stopping. When adolescents first start smoking, few expect to have trouble quitting. However, more than half of smoking teens say they try to quit every year, and fewer than 20% of those who smoke ten or more cigarettes per day say they are successful for even a month. Treatment of tobacco addiction rely mainly on the behavioral interventions as medications safety are not assessed for those less than 18 years old, so more research should be encouraged to find about the safety and availability for alternatives as behavioral intervention is not suitable alone for moderate to severe cases, Tobacco products are used by youth in a variety of ways,When smoking cessation efforts are undertaken in developed and developing nations, the wide diversity of tobacco products must be taken into consideration.

This research deals with the causes of tobacco dependence among young people, diagnosis and treatment methods.
Role of Primary Care Physician in COVID-19 Response: A Review
Authors: Algaows Faisal Suliman , Elias Amro Youssef A. , Alshaikh Abdulwahab Abdulmannan M. , Nabzah Rawan Saleh , Almejewil Anas Ebrahim , Fouly Daad Taha , Al Mubarak Zainab Jaber A. , Al Dosary Mossab Mohammad F. , Alnaim Abdullah Adel A. , Dhabaan Abdulaziz Aoudah T. Al , Abdali Yousef Ali , Alkhulayfi Abdulrahman Abdullah , Alkhalaf Mohammad Rajab , Alibrahem Abdulmajeed Mohammad S.
Published: January 2022

All healthcare providers have had to adapt and be flexible in order to respond to COVID-19. Nonetheless, the emphasis, particularly at the start of the outbreak, was on the impact and response of secondary and tertiary care. The primary care sector's responsibilities in the response focused on how it could help secondary and tertiary care centers respond. A small percentage of current research and evidence focuses on health services implications or applied public health approaches, with even fewer on the role of primary care and family medicine providers. So, while our scientific understanding of the virus and its subsequent clinical consequences has grown exponentially, information about primary care responses to COVID-19 in a variety of settings, as well as the interaction with patient perspectives and priorities, and broader public health responsibilities, remains significantly hazier.
Management of Chemotherapy Induced Mucositis
Authors: Noorsaeed Ashwag Siddik , Aljohani Mawaddah Saad , BinAfif Khawlah Salem A. , Alsaywed Rafal Abdulrahman , Bakhshwain Maha Ali , Alharbi Reham Mohammed , Bukhari Heba Abdulhakeem M. , Albalushi Omar Mohammed , Aljuhani Ahmad Abdulrahman , Batarfi Amal Abdullah , Subahi Awatif Fakhri , Alghamdi Azzah Mohammed S , Khallaf Moyssar tariq , Asiri Zainah Ali
Published: January 2022

Oral mucositis is a severe ailment that causes erythema, edema, and ulceration of the oral mucosa, as well as pain and oral intake restrictions. Chemotherapy and radiation therapy are the most often utilized cancer treatment options. Despite the fact that these treatments are used to improve a patient's quality of life, they are linked to a number of negative side effects. Oral mucositis is a common side effect in patients undergoing head and neck radiation therapy. While some chemotherapy-related side effects are being better managed, mucositis is becoming more common. Reducing patient risk factors, adopt proven preventative measures, and optimize supportive care practices targeted to the patients' needs and symptoms are all recommendations that can be made. In clinical practice and research, a variety of measures have been used to record the amount and severity of oral mucositis. The World Health Organization (WHO) scale is a simple, easy-to-use scale that can be used in clinical practice on a regular basis. There are multiple approaches for management of Mucositis.  Cryotherapy, palifermin, and sucralfate are among the three therapies that showed statistically significant effect in avoiding or lowering the severity of mucositis according to reports. In this article we’ll be looking at Chemotherapy induced mucositis, its etiology, epidemiology, evaluation. And most importantly management.
Preoperative Management of Diabetic Patients, an Overview
Authors: Abood Hashem Bark Awadh , Al-Qadhi Ali Ahmed , Alhindi Ossama Saed , Al Sheef Mohammed Jaafar A. , Alwadani Abdullah Saleh Salman , Alsaddah Nura Jamal T. , Mimish Sulaiman Mohammed , Alabdulwahab Abdulelah Ahmed , Basardah Ammar Abdullah , Musa Mohamed Eltahir , Alrashdi Abdullah Suwaymil , Alzahrani Khalid Mohsen , AlJohani Bassam Ibrahim , Alshehri Batool Mohammed S.
Published: January 2022

Glycemic control is critical in the perioperative setting, especially in diabetic patients. The consequences of surgical tension and anesthesia on blood sugar levels are distinct, and should be considered in order to maintain optimal glycemic control. Each stage of surgery presents its own set of challenges in terms of keeping glucose levels within the target range. Furthermore, there are some surgical conditions that necessitate specific glucose management protocols. Authors hope to highlight the most crucial factors to consider when developing a perioperative diabetic regimen, while still allowing for specific adjustments based on sound clinical judgement. Overall, by carefully managing glycemic control in perioperative patients, we may be able to reduce morbidity and mortality while improving surgical outcomes.
Anticancer Activity of "Ziziphus jujuba" - A Review
Authors: Rekha U. Vidhya , Bhuminathan S. , Shankar P. Ravi
Published: January 2022

Ziziphus jujuba Mill. (Z. jujube) is a conventional plant that has a long history of usage in nutrients and the therapeutic interventions of a wide range of ailments. It grows mainly in South and East Asia, and also in Australia and Europe. Mounting data supports the health advantages of Z. jujuba, including anticancer, anti-inflammation, anti-obesity, antioxidant, and hepato- and gastrointestinal protective characteristics. Chemotherapy, particularly with cis-diamminedichloroplatinium (CDDP, cisplatin) and its derivatives, is commonly used to treat cancer. Although it is an effective therapy for human tumors, drug resistance impedes successful treatment. A better knowledge of the processes and develop strategies to address chemoresistance can improve patient outcomes dramatically. Numerous researchers have recently focused their attention on the increasing occurrence of numerous types of malignancies worldwide. The anticancer efficacy of Z. jujuba was discussed in this review study.
Effectiveness of Chilled Cabbage Leaves Versus Hot Application on Breast Engorgement among Postnatal Mothers in Selected Hospitals of Vadodara, Gujarat, India
Authors: Rathava Usha , Kumary T. Vinaya
Published: January 2022

Background of the study: Breast feeding is important imperious in the mother’s life.  Breast milk may be complete healthy and salubrious supplement for the baby to help of the conjointly growth and development [1]. Breast engorgement causes discomfort and tenderness and pain that affect breastfeeding mothers early in the postpartum. The breast engorgement is one of the main factors contributing to early interruption of breastfeeding. Very few researches have been proven to monitor the effect of cabbage leaves application on breast engorgement [2].

Methodology: A quasi-experimental design two group pretest posttest design was used. A conceptual framework of Imogene king goal attainment model (1981) used for the conceptualization of the study. Total samples of 40 postnatal mothers were selected for the study using non probability purposive sampling technique. The samples divided in two experimental groups i.e. 20 in chilled cabbage leaves and 20 in hot application (temperature 43-46 degree Celsius - and tool used sociodemographic, pain scale & breast engorgement checklist and post test data collected after the intervention on 3rd day.

Results: Both the intervention, chilled cabbage leaves and hot application were effective and reduced pain in postnatal mothers (p=0.001*) at p<0.05 level.  In chilled cabbage leaves & hot application are equally effective in reduced breast engorgement in postnatal mothers (p=0.001*) at p<0.05 level.

Conclusion: Findings of chilled cabbage leaves and hot application were effective and reduced pain and breast engorgement among postnatal mothers.
Anthropometric Evaluation of Volume of Maxillary Sinus and Nasal Septum Patterns as an AID in Personal Identification Using CBCT-A Retrospective Study
Authors: Chandak Rakhi , Chandak Manoj , Thakare Pranali , Sathawane Ramhari , Bansod Runal , Deshmukh Pranada , Sukhadeve Vidyarjan , Akhtar Zareesh , Tayade Charwak
Published: January 2022

Aims: To determine the reliability and accuracy of maxillary sinus volume and nasal septum patterns in personal identification in forensics using CBCT (cone beam computed tomography).

Study Design: Retrospective Study

Place and Duration of Study: Department of Oral Medicine and Radiology, Swargiya Dadasaheb Kalmegh Smruti Dental College and Hospital Nagpur, from September 2019-December 2019.

Methodology: 110 CBCT scans of bilateral maxillary sinuses and nasal septum images were retrospectively obtained from the Oral Medicine and Radiology database (68 men and 42 females). The study was divided into two groups based on age. Group

-I consists of 58 CBCT scans taken between the ages of 20 and 40, while Group -II consists of 52 CBCT scans taken between the ages of 41 and 80. The height, breadth, and depth of the maxillary sinus were measured linearly. The nasal septum was classed as simple deviation to the right or left, sigmoid type, reverse sigmoid type, and straight based on the septa's deviations. Each person's combined maxillary sinus and nasal septum pattern was documented.

Results: The difference in maxillary sinus volume between two age groups was significant (P<0.5). In age group I, there was a substantial change in the left deviation pattern, and there was a significant change in the reverse sigmoid pattern in males and the straight nasal septum pattern in females. With whatever nasal septum configuration, there were no volumetric alterations(P>0.5).

Conclusion: In future, further research will be needed with a larger number of images to compare in order to arrive at a definitive identification.
Diagnosis and Therapy of Patients with Colorectal Cancer Metastases, Endovascular Approach
Authors: Khamidova Madina Idrisovna , Komplektova Diana Igorevna , Kosyan Irina Armenovna , Madayeva Aishat Aisayeva , Pshikhopova Sanyat Zaurbekovna , Gonian Meri Martinovna , Kumacheva Mariia Sergeevna , Sherifova Elvira Nazimovna , Maslova Alina Yurievna
Published: January 2022

According to current data, in Europe and North America, primary colon carcinoma diseases are detected with a frequency of 60-75 cases per 100 thousand population. In Russia over the past 10 years, there are up to 40-46 thousand cases annually. Active surgical tactics in the treatment of patients with colorectal cancer metastases in the liver can increase the overall survival time. The study showed that with the use of chemotherapy, the life expectancy of patients increases. Various options for complex treatment of patients with colorectal cancer metastases in the liver, especially with the use of endovascular and radiofrequency interventions, are relatively safe and effective, provided they are carried out in specialized oncological and coloproctological hospitals.
Thermodynamic and biophysical study of fatty acid effector binding to soybean lipoxygenase: implications for allostery driven by helix α2 dynamics
Authors: Roberts Daniella E. , Benton Amy M. , Fabian‐Bayola Claire , Spuches Anne M. , Offenbacher Adam R.
Published: January 2022

Previous comparative kinetic isotope effects have inferred an allosteric site for fatty acids and their derivatives that modulates substrate selectivity in 15‐lipoxygenases. Hydrogen–deuterium exchange also previously revealed regionally defined enhanced protein flexibility, centred at helix α2 – a gate to the substrate entrance. Direct evidence for allosteric binding and a complete understanding of its mechanism remains elusive. In this study, we examine the binding thermodynamics of the fatty acid mimic, oleyl sulfate (OS), with the monomeric model plant 15‐LOX, soybean lipoxygenase (SLO), using isothermal titration calorimetry. Dynamic light scattering and differential scanning calorimetry rule out OS‐induced oligomerization or structural changes. These data provide evidence that the fatty acid allosteric regulation of SLO is controlled by the dynamics of helix α2.
Liquid Crystal Templated Chiral Plasmonic Films with Dynamic Tunability and Moldability
Authors: Grzelak Dorota , Tupikowska Martyna , Vila‐Liarte David , Beutel Dominik , Bagiński Maciej , Parzyszek Sylwia , Góra Monika , Rockstuhl Carsten , Liz‐Marzán Luis M. , Lewandowski Wiktor
Published: January 2022

Thin films sustaining plasmonic circular dichroism (PCD) have acquired high scientific relevance and a great potential for applications. While most efforts in PCD thin film structures focus on lithographically fabricated static metasurfaces, the bottom‐up fabrication of active chiral plasmonic films constitutes an alternative approach. Herein, the preparation of PCD thin films by melting and freezing a mixture of liquid crystal (LC), a chiral dopant, and gold nanoparticles (Au NPs), serving as helical matrix, symmetry breaking inducer, and plasmonic component, respectively is reported. UV–vis and circular dichroism spectroscopies, as well as theoretical modeling are used to disclose the interactions among thin film components, toward maximizing the PCD dissymmetry factor (g‐factor). Variation of substrate temperature affords reversible off/on switching of the chiroptical response. The soft nature of LC matrix enables patterning of the films via a thermal nanoimprinting method, using a polydimethylsiloxane mold for transfer‐printing onto a flexible substrate, leading to stretchable PCD films. The PCD wavelengths can be readily tuned by varying the geometry of the Au NPs. This work provides an efficient technique to produce PCD thin films with active plasmonic properties and mechanical tunability.
A Universal Cosolvent Evaporation Strategy Enables Direct Printing of Perovskite Single Crystals for Optoelectronic Device Applications
Authors: Corzo Daniel , Wang Tonghui , Gedda Murali , Yengel Emre , Khan Jafar I , Li Ruipeng , Niazi Muhammad Rizwan , Huang Zhengjie , Kim Taesoo , Baran Derya , Sun Dali , Laquai Frédéric , Anthopoulos Thomas D. , Amassian Aram
Published: January 2022

Solution‐processed metal halide perovskite (MHP) single crystals (SCs) are in high demand for a growing number of printed electronic applications due to their superior optoelectronic properties compared to polycrystalline thin films. There is an urgent need to make SC fabrication facile, scalable, and compatible with the printed electronic manufacturing infrastructure. Here, a universal cosolvent evaporation (CSE) strategy is presented by which perovskite SCs and arrays are produced directly on substrates via printing and coating methods within minutes at room temperature from drying droplets. The CSE strategy successfully guides the supersaturation via controlled drying of droplets to suppress all crystallization pathways but one, and is shown to produce SCs of a wide variety of 3D, 2D, and mixed‐cation/halide perovskites with consistency. This approach works with commonly used precursors and solvents, making it universal. Importantly, the SC consumes the precursor in the droplet, which enables the large‐scale fabrication of SC arrays with minimal residue. Direct on‐chip fabrication of 3D and 2D perovskite photodetector devices with outstanding performance is demonstrated. The approach shows that any MHP SC can now be manufactured on substrates using precision printing and scalable, high‐throughput coating methods.
Closed‐Loop Temperature‐Controlled Magnetic Hyperthermia Therapy with Magnetic Guidance of Superparamagnetic Iron‐Oxide Nanoparticles
Authors: Ahmed Awais , Kim Eunhee , Jeon Sungwoong , Kim Jin‐Young , Choi Hongsoo
Published: January 2022

Hyperthermia therapy eliminates cancer cells by heating them above physiological temperatures. Superparamagnetic iron oxide nanoparticles (SPIONs) are promising for targeted hyperthermia therapy because of their excellent heating efficiency, biocompatibility, and active magnetic navigation. When exposed to a high‐frequency alternating magnetic field (AMF), SPIONs dissipate heat to damage cancer cells. Accurate temperature control is crucial for safe and efficient hyperthermia therapy. A closed‐loop temperature controller to control the temperature and heating rate by adjusting AMF’s strength, thereby enabling controllable hyperthermia therapy. Under a low‐frequency rotating magnetic field (RMF), the SPIONs form chains which can be actively manipulated towards the target by adjusting RMF’s direction, followed by AMF exposure for hyperthermia therapy. The SPIONs are precisely manipulated in a microfluidic chip and rat brain vessels ex vivo, highlighting the potential for targeted position control. Last, in vitro, and in vivo hyperthermia treatments are performed on human prostate cancer cells (PC3) and a PC3 xenograft mouse model using the proposed temperature controller, with tracking errors under 0.5°C and significant reduction in cancer cell viability and tumor volume. The magnetic locomotion with RMF, and the controlled heating using AMF, show the feasibility of using SPIONs for targeted hyperthermia therapy.
One‐Step MOF‐Templated Strategy to Fabrication of Ce‐Doped ZnIn2S4 Tetrakaidecahedron Hollow Nanocages as an Efficient Photocatalyst for Hydrogen Evolution
Authors: Fan Huitao , Jin Yujie , Liu Kecheng , Liu Weisheng
Published: January 2022

Achieving structure optimizing and component regulation simultaneously in the ZnIn2S4‐based photocatalytic system is an enormous challenge in improving its hydrogen evolution performance. 3D hollow‐structured photocatalysts have been intensively studied due to their obvious advantages in solar energy conversion reactions. The synthesis of 3D hollow‐structured ZnIn2S4, however, is limited by the lack of suitable template or synthesis methods, thereby restricting the wide application of ZnIn2S4 in the field of photocatalysis. Herein, Ce‐doped ZnIn2S4 photocatalysts with hollow nanocages are obtained via one‐step hydrothermal method with an ordered large‐pore tetrakaidecahedron cerium‐based metal–organic frameworks (Ce‐MOFs) as template and Ce ion source. The doping of Ce and the formation of ZnIn2S4 tetrakaidecahedron hollow nanocages with ultrathin nanosheet subunits are simultaneously induced by the Ce‐MOFs, making this groundbreaking work. The Ce‐doped ZnIn2S4 with a nonspherical 3D hollow nanostructure inherit the tetrakaidecahedron shape of the Ce‐MOF templates, and the shell is composed of ultrathin nanosheet subunits. Both theoretical and experimental results indicate that the doping of Ce and the formation of hollow nanocages increase light capture and the separation of photogenerated charge carriers.
Dual Role of Mo6S8 in Polysulfide Conversion and Shuttle for Mg–S Batteries
Authors: Wang Liping , Jankowski Piotr , Njel Christian , Bauer Werner , Li Zhenyou , Meng Zhen , Dasari Bosubabu , Vegge Tejs , Lastra Juan Maria García , Zhao‐Karger Zhirong , Fichtner Maximilian
Published: January 2022

Magnesium–Sulfur batteries are one of most appealing options among the post‐lithium battery systems due to its potentially high energy density, safe and sustainable electrode materials. The major practical challenges are originated from the soluble magnesium polysulfide intermediates and their shuttling between the electrodes, which cause high overpotentials, low sulfur utilization, and poor Coulombic efficiency. Herein, a functional Mo6S8 modified separator is designed to effectively address these issues. Both the experimental results and density functional theory calculations show that the electrochemically active Mo6S8 layer has a superior adsorption capability of polysulfides and simultaneously acts as a mediator to accelerate the polysulfide conversion kinetics. Remarkably, the magnesium–sulfur cell assembled with the functional separator delivers a high specific energy density (942.9 mA h g−1 in the 1st cycle) and can be cycled at 0.2 C for 200 cycles with a Coulombic efficiency of 96%. This work demonstrates a new design concept toward high‐performance metal–sulfur batteries.
Recycling of Lithium‐Ion Batteries—Current State of the Art, Circular Economy, and Next Generation Recycling
Authors: Neumann Jonas , Petranikova Martina , Meeus Marcel , Gamarra Jorge D. , Younesi Reza , Winter Martin , Nowak Sascha
Published: January 2022

Being successfully introduced into the market only 30 years ago, lithium‐ion batteries have become state‐of‐the‐art power sources for portable electronic devices and the most promising candidate for energy storage in stationary or electric vehicle applications. This widespread use in a multitude of industrial and private applications leads to the need for recycling and reutilization of their constituent components. Improving the “recycling technology” of lithium ion batteries is a continuous effort and recycling is far from maturity today. The complexity of lithium ion batteries with varying active and inactive material chemistries interferes with the desire to establish one robust recycling procedure for all kinds of lithium ion batteries. Therefore, the current state of the art needs to be analyzed, improved, and adapted for the coming cell chemistries and components. This paper provides an overview of regulations and new battery directive demands. It covers current practices in material collection, sorting, transportation, handling, and recycling. Future generations of batteries will further increase the diversity of cell chemistry and components. Therefore, this paper presents predictions related to the challenges of future battery recycling with regard to battery materials and chemical composition, and discusses future approaches to battery recycling.
Mapping Ambiphile Reactivity Trends in the Anti‐(Hetero)annulation of Non‐Conjugated Alkenes via PdII/PdIV Catalysis
Authors: Ni Hui‐Qi , Cooper Phillippa , Yang Shouliang , Wang Fen , Sach Neal , Bedekar Pranali G. , Donaldson Joyann S. , Tran‐Dubé Michelle , McAlpine Indrawan J. , Engle Keary M.
Published: January 2022

In this study, we systematically evaluate different ambiphilic organohalides for their ability to participate in anti‐selective carbo‐ or heteroannulation with non‐conjugated alkenyl amides under PdII/PdIV catalysis. Detailed optimization of the reaction conditions has led to protocols for synthesizing tetrahydropyridines, tetralins, pyrrolidines, and other carbo/heterocyclic cores via [n+2] (n=3–5) (hetero)annulation. Expansion of scope to otherwise unreactive ambiphilic haloketones through PdII/amine co‐catalysis is also demonstrated. Compared to other annulation processes, this method proceeds via a distinct PdII/PdIV mechanism involving Wacker‐type directed nucleopalladation. This difference results in unique reactivity and selectivity patterns, as revealed through assessment of reaction scope and competition experiments.
Chiral Hybrid Copper(I) Halides for High Efficiency Second Harmonic Generation with a Broadband Transparency Window
Authors: Ge Fei , Li Bo‐Han , Cheng Puxin , Li Geng , Ren Zefeng , Xu Jialiang , Bu Xian‐He
Published: January 2022

Chiral hybrid organic–inorganic metal halides (HOMHs) with intrinsic noncentrosymmetry have shown great promise for applications in second‐order nonlinear optics (NLO). However, established chiral HOMHs often suffer from their relatively small band gaps, which lead to negative impacts on transparent window and laser‐induced damage thresholds (LDT). Here, we have synthesized two chiral HOMHs based on CuI halides, namely (R‐/S‐MBA)CuBr2, which feature well‐balanced NLO performances with a highly efficient SHG response, outstanding optical transparency, and high LDT. The effective second‐order NLO coefficient of (R‐MBA)CuBr2 has been determined to be ≈24.7 pm V−1, which is two orders of magnitude higher than that of their CuII counterparts. This work shows the promising potential of CuI‐based chiral HOMHs for nonlinear photonic applications in wide wavelength regions.
Orbitale als Ausgangspunkt der Chemischen Bindung in Ge−Sb−Te‐Phasenwechselmaterialien**
Authors: Hempelmann Jan , Müller Peter C. , Ertural Christina , Dronskowski Richard
Published: January 2022

Schichtartige Phasenwechselmaterialien des Typs Ge−Sb−Te werden industriell zur Datenspeicherung verwendet und sind auch heute noch Gegenstand intensiver Forschung, um den quantenchemischen Ursprung ihrer Eigenschaften zu verstehen. Zur Analyse der zugrundeliegenden periodischen Wellenfunktion untersuchen wir die wechselwirkenden Atomorbitale einschließlich ihrer Phaseninformation mit Hilfe des Kristallorbitalbindungsindex und der Fragmentkristallorbitalanalyse. In voller Übereinstimmung mit Ergebnissen aus langreichweitigen projizierten Kraftkonstanten untermauern wir die besondere Rolle von Mehrzentrenbindungen entlang geradliniger atomarer Anordnungen. Ebendiese Mehrzentrenbindung ähnelt der bekannten Dreizentren‐Vierelektronenbindung in Molekülen, hat aber im festen Zustand weitreichende Auswirkungen für die üblicherweise als “metavalent” bezeichneten Materialeigenschaften und verdeutlicht die Zusammenhänge. Es liegt nahe, daß diese Mehrzentrenbindung die Ursache für das erstaunliche Bindungsbruch‐ und Phasenwechselverhalten sowie für die zu kleinen “van‐der‐Waals”‐Lücken zwischen den einzelnen Schichten ist.
Passerini–Smiles Reaction of α‐Ketophosphonates: Platform for Phospha‐Brook/Smiles Embedded Cascades
Authors: Cheibas Cristina , Fincias Nicolas , Casaretto Nicolas , Garrec Julian , El Kaïm Laurent
Published: January 2022

The Passerini–Smiles reactions of α‐ketophosphonates with nitrophenols has been used as a platform to observe complex cascades involving multiple Smiles transfers coupled with phospha‐Brook rearrangement. When using 4‐nitrophenols a rare 1,3‐Truce–Smiles rearrangement is observed leading to diarylacetamide derivatives. 2‐Nitro‐derivatives lead to a completely different reactivity pattern that may be explained by a nitro to nitroso conversion followed by a σ–π metathesis. All mechanistic assumptions are confirmed by DFT calculations performed on both families of adducts. The potential of this work has been further demonstrated by the use of N‐aryl α‐ketoamides as alternative starting materials for these cascades as well as the disclosure of new aza‐Nazarov access to hydroxy‐indolones.
A Plausible Prebiotic One‐Pot Synthesis of Orotate and Pyruvate Suggestive of Common Protometabolic Pathways
Authors: Clay Alyssa P. , Cooke Rachel E. , Kumar Ravi , Yadav Mahipal , Krishnamurthy Ramanarayanan , Springsteen Greg
Published: January 2022

A reaction between two prebiotically plausible building blocks, hydantoin and glyoxylate, generates both the nucleobase orotate, a precursor of biological pyrimidines, and pyruvate, a core metabolite in the citric acid cycle and amino acid biosynthesis. The reaction proceeds in water to provide significant yields of the two widely divergent chemical motifs. Additionally, the reaction of thiohydantoin and glyoxylate produces thioorotate in high yield under neutral aqueous conditions. The use of an open‐chain thiohydantoin derivative also enables the potential pre‐positioning of a nucleosidic bond prior to the synthesis of an orotate nucleoside. The observation that diverse building blocks of modern metabolism can be produced in a single reaction pot, from common reactants under mild conditions, supports the plausibility of orthogonal chemistries operating at the origins of chemical evolution.
Outstanding Multi‐Photon Absorption at π‐Delocalizable Metallodendrimers
Authors: Zhang Ling , Morshedi Mahbod , Humphrey Mark G.
Published: January 2022

Multi‐photon absorption (MPA) has attracted interest for applications exploiting the tight spatial control of interaction volume and long wavelength excitation. However, a deficiency of molecules exhibiting higher‐order nPA (n‐photon absorption, n>2) and a lack of structure–property studies to define the key structural characteristics needed to optimize higher‐order MPA performance have hindered practical development. We herein report the syntheses of second‐ and third‐generation metallodendrimers and assessment of their nonlinear absorption, together with those of zero‐ and first‐generation analogues. We report the first 5PA and 6PA data for an organometallic. The largest dendrimer exhibits exceptional three‐, four‐, five‐ and six‐photon absorption to femtosecond‐pulsed light. The systematically varied compounds highlight the crucial role of metal‐to‐oligo(phenyleneethynylene) charge transfer in promoting outstanding MPA activity.
Rhodium‐Catalyzed Stereoselective Deuteration of Benzylic C–H Bonds via Reversible η6‐Coordination
Authors: Kang Qi‐Kai , Li Yuntong , Chen Kai , Zhu Hui , Wu Wen‐Qiang , Lin Yunzhi , Shi Hang
Published: January 2022

We report a convenient method for benzylic H/D exchange of a wide variety of substrates bearing primary, secondary, or tertiary C−H bonds via a reversible η6‐coordination strategy. A doubly cationic [CpCF3RhIII]2+ catalyst that serves as an arenophile facilitates deprotonation of inert benzylic hydrogen atoms (pKa>40 in DMSO) without affecting other hydrogen atoms, such as those on aromatic rings or in α‐positions of carboxylate groups. Notably, the H/D exchange reactions feature high stereoretention. We demonstrated the potential utility of this method by using it for deuterium labeling of ten pharmaceuticals and their analogues.
Rheumatoid Factor and Anti–Modified Protein Antibody Reactivities Converge on IgG Epitopes
Authors: Mergaert Aisha M. , Zheng Zihao , Denny Michael F. , Amjadi Maya F. , Bashar S. Janna , Newton Michael A. , Malmström Vivianne , Grönwall Caroline , McCoy Sara S. , Shelef Miriam A.
Published: January 2022

Objective

Rheumatoid arthritis (RA) patients often develop rheumatoid factors (RFs), antibodies that bind IgG Fc, and anti–modified protein antibodies (AMPAs), multireactive autoantibodies that commonly bind citrullinated, homocitrullinated, and acetylated antigens. Recently, antibodies that bind citrulline‐containing IgG epitopes were discovered in RA, suggesting that additional undiscovered IgG epitopes could exist and that IgG could be a shared antigen for RFs and AMPAs. This study was undertaken to reveal new IgG epitopes in rheumatic disease and to determine if multireactive AMPAs bind IgG.

Methods

Using sera from patients with RA, systemic lupus erythematosus, Sjögren's disease (SjD), or spondyloarthropathy, IgG binding to native, citrulline‐containing, and homocitrulline‐containing linear epitopes of the IgG constant region was evaluated by peptide array, with highly bound epitopes further evaluated by enzyme‐linked immunosorbent assay (ELISA). Binding of monoclonal AMPAs to IgG‐derived peptides and IgG Fc was also evaluated by ELISA.

Results

Seropositive RA sera showed high IgG binding to multiple citrulline‐ and homocitrulline‐containing IgG‐derived peptides, whereas anti‐SSA+ sera from SjD patients showed consistent binding to a single linear native epitope of IgG in the hinge region. Monoclonal AMPAs bound citrulline‐ and homocitrulline‐containing IgG peptides and modified IgG Fc.

Conclusion

The repertoire of epitopes bound by AMPAs includes modified IgG epitopes, positioning IgG as a common antigen that connects the otherwise divergent reactivities of RFs and AMPAs.
Central Role of Semaphorin 3B in a Serum‐Induced Arthritis Model and Reduced Levels in Patients With Rheumatoid Arthritis
Authors: Igea Ana , Carvalheiro Tiago , Malvar‐Fernández Beatriz , Martinez‐Ramos Sara , Rafael‐Vidal Carlos , Niemantsverdriet Ellis , Varadé Jezabel , Fernández‐Carrera Andrea , Jimenez Norman , McGarry Trudy , Rodriguez‐Trillo Angela , Veale Douglas , Fearon Ursula , Conde Carmen , Pego‐Reigosa Jose M. , González‐Fernández África , Reedquist Kris A. , Radstake Timothy R. D. J. , van der Helm‐Van Mil Annette , García Samuel
Published: January 2022

Objective

Semaphorin 3B (Sema3B) decreases the migratory and invasive capacities of fibroblast‐like synoviocytes (FLS) in rheumatoid arthritis (RA) and suppresses expression of matrix metalloproteinases. We undertook this study to examine the role of Sema3B in a mouse model of arthritis and its expression in RA patients.

Methods

Clinical responses, histologic features, and FLS function were examined in wild‐type (WT) and Sema3B−/− mice in a K/BxN serum transfer model of arthritis. Protein and messenger RNA expression of Sema3B in mouse joints and murine FLS, as well as in serum and synovial tissue from patients with arthralgia and patients with RA, was determined using enzyme‐linked immunosorbent assay, immunoblotting, quantitative polymerase chain reaction, and RNA sequencing. FLS migration was determined using a wound closure assay.

Results

The clinical severity of serum‐induced arthritis was significantly higher in Sema3B−/− mice compared to WT mice. This was associated with increased expression of inflammatory mediators and increased migratory capacity of murine FLS. Administration of recombinant mouse Sema3B reduced the clinical severity of serum‐induced arthritis and the expression of inflammatory mediators. Sema3B expression was significantly lower in the synovial tissue and serum of patients with established RA compared to patients with arthralgia. Serum Sema3B levels were elevated in patients with arthralgia that later progressed to RA, but not in those who did not develop RA; however, these levels drastically decreased 1 and 2 years after RA development.

Conclusion

Sema3B expression plays a protective role in a mouse model of arthritis. In RA patients, expression levels of Sema3B in the serum depend on the disease stage, suggesting different regulatory roles in disease onset and progression.
The ALA5/ALA6/ALA7 repeat polymorphisms of the glutathione peroxidase‐1 (GPx1) gene and autism spectrum disorder
Authors: Carducci Federica , Ardiccioni Chiara , Fiorini Rosamaria , Vignini Arianna , Di Paolo Alice , Alia Sonila , Barucca Marco , Biscotti Maria Assunta
Published: January 2022

Autism is a severe neurodevelopmental disorder leading to deficits in social interaction, communication, and several activities. An increasing number of evidence suggests a role of oxidative stress in the etiology of autism spectrum disorder (ASD). Indeed, impaired antioxidant mechanisms may lead to the inadequate removal of H2O2 with a consequent increase in highly active hydroxyl radicals and other reactive oxygen species causing cellular damages. The GPx1 is one of the most important enzymes counteracting oxidative stress. In this work, we investigated a possible correlation between the GCG repeat polymorphism present in the first exon of GPx1 gene encoding a tract of five to seven alanine residues (ALA5, ALA6, and ALA7) and ASD. Our findings highlighted a high frequency of ALA5 allele in ASD subjects. Moreover, proteins corresponding to the three GPx1 variants were produced in vitro, and the evaluation of their activity showed a lower values for GPx1 having ALA5 polymorphism. The comparison of the secondary and tertiary structure predictions revealed an alpha‐helix in correspondence of alanine stretch only in the case of GPx1‐ALA7 variant. Finally, to better investigate protein structure, steady‐state fluorescence measurements of GPx1 intrinsic tryptophan were carried out and the three tested proteins exhibited a different stability under denaturing conditions. This work demonstrates the importance in adopting a multidisciplinary strategy to comprehend the role of GPx1 in ASD.

Lay Summary

Results here obtained suggest a possible role of ALA5 GPx1 variant in ASD. However, given the multifactorial nature of autism, this evidence might be a piece of a more complex puzzle being the GPx1 enzyme part of a complex pathway in which several proteins are involved.
Nine‐fold symmetry of centriole: The joint efforts of its core proteins
Authors: Tian Yuan , Yan Yuxuan , Fu Jingyan
Published: January 2022

The centriole is a widely conserved organelle required for the assembly of centrosomes, cilia, and flagella. Its striking feature – the nine‐fold symmetrical structure, was discovered over 70 years ago by transmission electron microscopy, and since elaborated mostly by cryo‐electron microscopy and super‐resolution microscopy. Here, we review the discoveries that led to the current understanding of how the nine‐fold symmetrical structure is built. We focus on the recent findings of the centriole structure in high resolution, its assembly pathways, and its nine‐fold distributed components. We propose a model that the assembly of the nine‐fold symmetrical centriole depends on the concerted efforts of its core proteins. Also see the video abstract here:https://youtu.be/m4h_3II_WJo
Oxidative Stress in Cancer Therapy: Friend or Enemy?
Authors: Azmanova Maria , Pitto‐Barry Anaïs
Published: January 2022

Excessive cellular oxidative stress is widely perceived as a key factor in pathophysiological conditions and cancer development. Healthy cells use several mechanisms to maintain intracellular levels of reactive oxygen species (ROS) and overall redox homeostasis to avoid damage to DNA, proteins, and lipids. Cancer cells, in contrast, exhibit elevated ROS levels and upregulated protective antioxidant pathways. Counterintuitively, such elevated oxidative stress and enhanced antioxidant defence mechanisms in cancer cells provide a therapeutic opportunity for the development of drugs with different anticancer mechanisms of action (MoA). In this review, oxidative stress and the role of ROS in cells are described. The tumour‐suppressive and tumour‐promotive functions of ROS are discussed, and these two different therapeutic strategies (increasing or decreasing ROS to fight cancer) are compared. Clinically approved drugs with demonstrated oxidative stress anticancer MoAs are highlighted followed by description of examples of metal‐based anticancer drug candidates causing oxidative stress in cancer cells via novel MoAs.
Molecular Determinants of Carbocation Cyclisation in Bacterial Monoterpene Synthases
Authors: Leferink Nicole G. H. , Escorcia Andrés M. , Ouwersloot Bodi R. , Johanissen Linus O. , Hay Sam , van der Kamp Marc W. , Scrutton Nigel S.
Published: January 2022

Monoterpene synthases are often promiscuous enzymes, yielding product mixtures rather than pure compounds due to the nature of the branched reaction mechanism involving reactive carbocations. Two previously identified bacterial monoterpene synthases, a linalool synthase (bLinS) and a cineole synthase (bCinS), produce nearly pure linalool and cineole from geranyl diphosphate, respectively. We used a combined experimental and computational approach to identify critical residues involved in bacterial monoterpenoid synthesis. Phe77 is essential for bCinS activity, guiding the linear carbocation intermediate towards the formation of the cyclic α‐terpinyl intermediate; removal of the aromatic ring results in variants that produce acyclic products only. Computational chemistry confirmed the importance of Phe77 in carbocation stabilisation. Phe74, Phe78 and Phe179 are involved in maintaining the active site shape in bCinS without a specific role for the aromatic ring. Phe295 in bLinS, and the equivalent Ala301 in bCinS, are essential for linalool and cineole formation, respectively. Where Phe295 places steric constraints on the carbocation intermediates, Ala301 is essential for bCinS initial cyclisation and activity. Our multidisciplinary approach gives unique insights into how carefully placed amino acid residues in the active site can direct carbocations down specific paths, by placing steric constraints or offering stabilisation via cation‐π interactions.
Human satellite III long noncoding RNA imparts survival benefits to cancer cells
Authors: Chatterjee Manjima , Sengupta Sonali
Published: January 2022

Long noncoding RNAs (lncRNAs) are heterogeneous group of transcripts that lack coding potential and have essential roles in gene regulations. Recent days have seen an increasing association of noncoding RNAs with human diseases, especially cancers. One interesting group of noncoding RNAs strongly linked to cancers are heterochromatic repetitive Satellite RNAs. Satellite RNAs are transcribed from pericentromeric heterochromatic region of the human chromosomes. Satellite II RNA, most extensively studied, is upregulated in wide variety of epithelial cancer. Similarly, alpha satellite is over expressed in BRCA1‐deficient tumors. Though much is known about alpha satellites and SatII repeats, little is known about Satellite III (SatIII) lncRNAs in human cancers. SatIII repeats, though transcriptionally silent in normal conditions is actively transcribed under condition of stress, mainly heat shock. In this study, we show that colon and breast cancer cells aberrantly transcribes SatIII, in a heat shock factor I (HSF1)‐independent manner. Our study also reveals that, the overexpression of SatIII RNA favors cancer cell survival by overriding chemo drug‐induced cell death. Interestingly, knockdown of SatIII sensitizes cells toward chemotherapeutic drugs. This sensitization is possibly mediated by restoration of p53 protein expression that facilitates cell death. Heat shock however helps SatIII to continue with its pro‐cell survival function. Our results, therefore suggest SatIII to be an important regulator of human cancers. Induction of SatIII is not only a response to the oncogenic stress but also facilitates cancer progression by a distinct pathway that is different from heat stress pathway.
Airway malacia in premature infant twins with bronchopulmonary dysplasia: Two case reports
Authors: Yang Wanwan , Zhang Jiuxiang , Lu Dongxue , Zhang Haopeng
Published: January 2022

Premature infants who require surgery for retinopathy of prematurity often exhibit bronchopulmonary dysplasia. Reactive airway is a clinical manifestation of bronchopulmonary dysplasia. We describe premature infant twins who had difficulty with positive pressure ventilation during anesthesia. Both cases occurred during induction of anesthesia for binocular anterior chamber puncture and vitreous cavity injection. The most likely cause in each case was airway malacia. We recommend that endotracheal intubation is performed in infant patients with low body weight; the possibility of airway malacia occurrence should be considered, especially for infants with comorbid bronchopulmonary dysplasia.
Evidence for Charge Delocalization in Diazafluorene Ligands Supporting Low‐Valent [Cp*Rh] Complexes**
Authors: Henke Wade C. , Stiel Jonah P. , Day Victor W. , Blakemore James D.
Published: January 2022

Ligands based upon the 4,5‐diazafluorene core are an important class of emerging ligands in organometallic chemistry, but the structure and electronic properties of these ligands have received less attention than they deserve. Here, we show that 9,9′‐dimethyl‐4,5‐diazafluorene (Me2daf) can stabilize low‐valent complexes through charge delocalization into its conjugated π‐system. Using a new platform of [Cp*Rh] complexes with three accessible formal oxidation states (+III, +II, and +I), we show that the methylation in Me2daf is protective, blocking Brønsted acid‐base chemistry commonly encountered with other daf‐based ligands. Electronic absorption spectroscopy and single‐crystal X‐ray diffraction analysis of a family of eleven new compounds, including the unusual Cp*Rh(Me2daf), reveal features consistent with charge delocalization driven by π‐backbonding into the LUMO of Me2daf, reminiscent of behavior displayed by the workhorse 2,2′‐bipyridyl ligand. Taken together with spectrochemical data demonstrating clean conversion between oxidation states, our findings show that 9,9′‐dialkylated daf‐type ligands are promising building blocks for applications in reductive chemistry and catalysis.
Novel highly efficient absolute optical resolution method by serial combination of two asymmetric reactions from acetylene monomers having racemic substituents
Authors: Tang Yanan , Liu Lijia , Suzuki Junpei , Teraguchi Masahiro , Kaneko Takashi , Aoki Toshiki
Published: January 2022

For general optical resolution, an optical resolution agent is necessary, and the best agent should be selected for each racemic compound. In this study, we will report that a novel optical resolution method by circularly polarized light (CPL) without any optical resolution agents has been developed by serially connecting two enantioselective reactions. These reactions we developed are the enantiomer‐selective helix‐sense‐selective polymerization (ES‐HSSP) and helix‐sense‐selective highly selective photocyclic aromatization (SCAT) by CPL (HS‐SCAT). Since this significantly unique EPHS method (EPHS = ES‐HSSP + HS‐SCAT) does not need any optical resolution agents, any cocatalysts, and solvents for the selective decomposition reaction (HS‐SCAT), this process is quite simple and convenient. Since this process does not include any decomposition of the target racemates themselves, both enantiomers could be obtained. The optical yields for isolated compounds that were enantiomerically separated by the EPHS method were very high, for example, 78%ee, 93%ee, and 85%ee for menthol, phenethyl alcohol, and 2‐butanol, respectively. In addition, their chemical yields were around 85% to 94%. Therefore, the EPHS method was found to show an excellent performance and can be applied to actual optical resolution for a wide range of racemic compounds. This is the first absolute optical resolution by CPL showing high optical and chemical yields and expected to become a practical optical resolution method.