bluuebunny/crossref_metadata_2025 huggingface dataset:
Cerebrovascular diseases: hemostasis and biomarkers
Authors: Танашян М.М. , Раскуражев А.А. , Шабалина А.А. , Ройтман Е.В.
Published: February 2021

Введение. Сосудистые заболевания головного мозга остаются одним из наиболее важных вызовов современному здравоохранению в связи с высокими показателями смертности и инвалидизации. Одним из ведущих этиопатогенетических моментов развития и прогрессирования ишемических цереброваскулярных заболеваний (ЦВЗ) являются нарушения гемореологии и гемостаза.
Цель исследования: оценка ряда параметров гемореологии и гемостаза, а также биомаркерного профиля у пациентов с ишемическими ЦВЗ.
Материалы и методы. В исследование включены 454 пациента (средний возраст — 66,3 ± 8,1 лет; мужчины — 56%) со стенозами внутренней сонной артерии (ВСА) не менее 50% от общего просвета. Наряду с общеклиническим и детальным неврологическим осмотром больным проводили дуплексное сканирование сонных и позвоночных артерий,
МРТ головного мозга, взятие образцов крови как для рутинных клинического и биохимического анализов крови, гемореологических и коагулологических показателей, так и для определения плазменной концентрации и активности основных биомаркеров сосудистых заболеваний головного мозга.
Результаты. Продемонстрировано, что сам факт наличия атеросклеротического поражения в системе ВСА сопровождается значимыми изменениями систем гемореологии и гемостаза. На основании линейки биомаркеров была разработана шкала, отражающая риск прогрессирования атеросклероза, в соответствии с которой увеличение балла соответствует ухудшению течения ЦВЗ.
Заключение. Выявленные изменения показателей крови отражают сложность и многогранность патогенетических аспектов развития ЦВЗ. Вместе с тем исследованные биомаркеры могут быть использованы в качестве инструмента предикторной оценки риска прогрессирования сосудистой патологии головного мозга.

Introduction. Cerebrovascular diseases (CVD) present a major concern for modern healthcare due to high mortality and disability rates. Hemorheological and hemocoagulation disturbances play one from main etiopathogenetic aspects in the development and progression of CVD.
Aim: to estimate some hemorheological and hemostasis parameters together with biomarker profi le in patients with ischemic CVD.
Materials and methods. The study comprised 454 patients (mean age — 66.3 ± 8.1 years; men — 56%) with > 50% internal carotid artery (ICA) stenosis. Along with a thorough clinical and neurological examination, the patients underwent carotid ultrasound, brain MRI, and blood analyses, including hemorheological and hemostasis parameters as well as biomarkers of CVD.
Results. It has been demonstrated that the presence of atherosclerotic lesions of the ICA is associated with profound changes in hemorheology and hemostasis. The biomarker profile allowed us to develop a risk scale of CVD progression — with the highest score corresponding to the greatest risk.
Conclusion. The found blood alterations represent the complexity of CVD pathogenesis. The studied biomarkers may be used as a predicting tool for evaluating the risk of CVD progression.
Individual approach to postoperative thromboprophylaxis in oncology
Authors: Кательницкая О.В. , Кит О.И. , Кательницкий И.И. , Гуськова Н.К. , Аванесова К.А.
Published: February 2021

Цель исследования: повысить эффективность профилактики венозных тромбоэмболических осложнений (ВТЭО) у онкологических больных на хирургическом этапе лечения.
Материалы и методы. Проанализированы результаты антикоагулянтной профилактики ВТЭО в послеоперационном периоде у 216 больных с высоким риском тромбоза, обусловленным злокачественными новообразованиями (ЗНО) желудочно-кишечного тракта. В динамике сравнивали результаты показателей коагулограммы, нового глобального теста оценки гемостаза и ультразвукового исследования триплексного сканирования венозной системы нижних конечностей в течение 1 месяца.
Результаты. Наибольшее количество ВТЭО зарегистрировано в группе без использования медикаментозной профилактики (26,9%) после оперативного вмешательства. Наименьшая частота ВТЭО отмечена в группе с индивидуальным подбором дозы антикоагулянта (4,9%) на основании глобального теста оценки гемостаза.
Заключение. Полагаем, что в послеоперационном периоде у больных со ЗНО желудочно-кишечного тракта необходима комплексная оценка состояния свертывающей системы с коррекцией режима антикоагулянтной профилактики на основании динамики показателей гемостаза, что позволяет снизить частоту ВТЭО.

Aim: to increase prophylaxis eff ectiveness of venous thromboembolic complications (VTE) in cancer patients under surgery.
Materials and methods. We analyzed the results of anticoagulant postoperative VTE prophylaxis in 216 patients with high risk of thrombosis due to malignant neoplasms of gastrointestinal tract. In dynamics we compared coagulogram parameters, the results of new global hemostatic assessment test, and ultrasound triplex scan of lower limbs venous system during 1 month.
Results. Most VTE cases were registered in patients without medicamentous prophylaxis (26.9%) after surgery. The lowest VTE frequency was observed in patients with individual anticoagulant dose selection (4.9%) based on the global hemostatic assessment test.
Conclusion. We consider that in postoperative period in patients with malignant neoplasms of gastrointestinal tract integrated assessment of coagulation system and correction of anticoagulant prophylaxis regimen based on the dynamics of hemostasis parameters are required that allows to reduce VTE frequency.
The possibility to obtain reagent from platelet concentrates with long storage time for determination of von Willebrand factor ristocetin cofactor activity (vWF:RCo)
Authors: Берковский А.Л. , Сергеева Е.В. , Суворов А.В. , Иевская К.Н. , Анисимова Е.В.
Published: February 2021

Введение. Фактор Виллебранда (ФВ) является важным компонентом системы гемостаза, и отклонение от нормы его содержания или состава вызывает развитие различных типов болезни Виллебранда. Определение ристоцетин-кофакторной активности ФВ (ФВ:РКФА) является особенно значимым при выявлении таких типов болезни Виллебранда как 2А, 2В и 2М, при которых содержание антигена ФВ находится в нормальных пределах, а ФВ:РКФА значительно снижена.
Цель исследования: получение реагента для измерения ФВ:РКФА из концентратов тромбоцитов с длительным сроком хранения, обеспечивающего правильность диагностики.
Материалы и методы. Функционально полноценные тромбоциты получали из донорских тромбоцитарных концентратов со сроком хранения 7–14 суток.
Результаты. При создании реагента для измерений ФВ:РФКА нами был подобран метод отбора функционально полноценных донорских тромбоцитов для получения фиксированных формальдегидом клеток. На основе таких тромбоцитов был разработан реагент, позволяющий измерять ФВ:РКФА с использованием как агрегационного, так и агглютинационного метода. Выявлено соответствие результатов определения ФВ обоими методами с коэффициентом корреляции 0,96. Проведена оценка агрегационного метода измерения ФВ:РКФА по результатам участия в международной программе внешнего контроля качества UK NEQAS for Blood Coagulation (Великобритания).
Заключение. Показано, что использование полученного из фиксированных тромбоцитов реагента позволяет правильно измерять ФВ:РКФА.

Introduction. Von Willebrand factor (vWF) is an important component of hemostatic system and deviations from the norm of its content or composition are the cause of various types of von Willebrand disease development. Determination of ristocetin-cofactor activity of vWF (vWF:RCo) is particularly important for identifying 2A, 2B and 2M types of von Willebrand disease, in which the content of vWF antigen is within the normal range, and vWF:RCo signifi cantly reduced.
Aim: to obtain a reagent for the measurement of vWF:RCo from platelet concentrates with a long shelf life, providing correct diagnostics.
Materials and methods. Fully functional platelets were obtained from donor platelet concentrates with a shelf life of 7–14 days.
Results. We discovered the method for selection of fully functional donor platelets to produce formaldehyde-fi xed cells. On the basis of these platelets we developed a reagent that allows to measure vWF:RCo using both aggregation and agglutination methods. The appropriateness was found between the results of vWF determination by both methods with a correlation coeffi cient 0.96. The aggregation method of measuring vWF:RCo was evaluated by a result of participation in the international program of external quality control UK NEQAS for Blood Coagulation (United Kingdom).
Conclusion. It is shown that the use of a reagent obtained from fi xed platelets allows for the correct measurement of vWF:RCo.
Prothrombin complex concentrate in therapy of massive postpartum hemorrhage
Authors: Прасолов Н.В. , Буланов А.Ю. , Шулутко Е.М. , Яцков К.В. , Щербакова О.В. , Коняшина Н.И.
Published: February 2021

Введение. Тяжелые послеродовые кровотечения остаются одной из основных причин материнской смертности. Своевременная диагностика нарушений в системе гемостаза и целенаправленная гемостатическая терапия с включением концентратов факторов свертывания может способствовать уменьшению трансфузионной нагрузки и остановке кровотечения.
Цель исследования: оценить эффективность концентрата протромбинового комплекса (КПК) «Протромплекс 600» для лечения тяжелых послеродовых кровотечений.
Материалы и методы. В исследование включены 44 женщины, которым вводили КПК в комплексной терапии тяжелых послеродовых кровотечений. Осуществляли контроль состояния гемостаза до и после введения препарата с помощью стандартных коагулологических тестов и тромбоэластографии (ТЭГ). Показания для введения КПК: тяжелое послеродовое кровотечение, гипокоагуляция по плазменному звену гемостаза, по данным ТЭГ, увеличение международного нормализованного отношения ≥ 1,5. Результаты. Замедление темпа кровотечения с последующей остановкой достигнута у 38 (86%) рожениц после однократного введения КПК в дозе 10–25 МЕ/кг. Не зафиксировано каких-либо побочных реакций на введение препарата, в том числе тромбогенных осложнений. Уровень антитромбина III у пациенток после инфузии «Протромплекса» не выходил за рамки референсных значений.
Заключение. Хороший терапевтический эффект КПК у данной категории больных подтверждает клиническую целесообразность и патогенетическую обоснованность его введения для быстрой коррекции дефицита основных факторов свертывания.

Introduction. Severe postpartum hemorrhage remains one of the main causes of maternal mortality. In-time diagnosis of coagulation disorders and targeted therapy, with incorporation of coagulation’s factor concentrates, can help reduce blood components consumption and stop bleeding.
Aim: to assess the eff ectiveness of prothrombin complex concentrate (PCC) «Protromplex 600» for treatment of severe postpartum hemorrhage.
Materials and methods. PCC was used in complex therapy of severe postpartum hemorrhage in 44 women. Hemostasis was monitored before and after PCC administration using standard coagulological tests and thromboelastography (TEG). Indications for PCC administration: severe postpartum hemorrhage, hypocoagulation in plasma hemostasis link, hypocoagulation according to TEG, increased international normalized ratio ≥ 1.5.
Results. Decreasing of bleeding rate with its subsequent stopping was achieved in 38 (86%) post-delivery women after single PCC administration at dose 10–25 IU/kg. No adverse reactions to PCC administration, including thrombogenic complications were fi xed. After «Protromplex 600» infusion antithrombin III level was within the reference values.
Conclusion. A good therapeutic effect of CCP in this category of patients confirms the clinical advisability and pathogenetic validity of its administration for the rapid correction major coagulation factors deficiency.
Combined thrombophilia according to hematological consultation data
Authors: Волкова С.А.
Published: February 2021

Введение. Диагностическая значимость гомозиготной мутации генов факторов свертывания крови FV Leiden и FII, а также их гетерозиготного полиморфизма в сочетании с маркерами первичного антифосфолипидного синдрома как предикторов тромбоза остается неоднозначной.
Цель исследования: представить клинические случаи сочетанных тромбофилий, выявленных в процессе амбулаторного гематологического консультирования.
Материалы и методы. В базе данных приема гематолога с января 2012 г. по апрель 2017 г. выявлен 891 пациент (837 женщин и 54 мужчины), которым было проведено обследование и консультирование на предмет тромбофилии и/или наличия активных факторов тромбогенного риска.
Результаты. Сочетанная тромбофилия выявлена у 7 (0,8%) из 891 обследованного или у 7 (2,8%) из 246 пациентов
с факторами тромбогенного риска. В 4 случаях у 2 мужчин (44 и 28 лет) и у 2 женщин (29 и 33 лет) диагноз установлен в связи с тяжелой и/или рецидивирующей венозной и артериальной тромбоэмболией и у 3 женщин (27, 36 и 39 лет) в связи с синдромом потери плода.
Заключение. Анализ наблюдений подтверждает целесообразность поиска сочетанной тромбофилии в случае рецидивирующего тромбоза для выбора оптимальной антикоагулянтной терапии.

Introduction. The diagnostic signifi cance of homozygous mutation of FV Leiden and FII clotting factor genes, as well as their heterozygous polymorphism in combination with the markers of the primary antiphospholipid syndrome as predictors of thrombosis remains ambiguous.
Aim: to present clinical cases of combined thrombophilia revealed during outpatient hematology counseling.
Materials and methods. In hematologist database from January 2012 to April 2017 we found 891 patients (837 women and 54 men) who were examined and consulted for thrombophilia and/or presence of active factors of thrombogenic risk.
Results. Combined thrombophilia was identifi ed in 7 (0.8%) of 891 patients or in 7 (2.8%) of 246 patients with thrombogenic risk factors. In 4 cases — 2 men (44 and 28 years) and 2 women (29 and 33 years old) had a diagnosis due to severe and/or recurrent venous and arterial thromboembolism and 3 women (27, 36 and 39 years) had a diagnosis due to fetal loss syndrome.
Conclusion. The observations confi rm the practicability of researching for combined thrombophilia in case of recurrent thrombosis for the choice of optimal anticoagulant therapy.
Clinical case of laparoscopic successful removal of a giant benign ovarian tumor in patient after heart transplantation
Authors: Лапина И.А. , Гаврилов М.В. , Кольтинова Т.Г. , Доброхотова Ю.Э. , Дубнер Е.Ю.
Published: February 2021

В течение последних десятилетий трансплантация сердца получила широкое распространение в мировой практике. Литературных данных, рассматривающих алгоритмы ведения пациентов после пересадки сердца, требующих оперативного вмешательства, недостаточно. Нами описан клинический случай успешного удаления гигантского доброкачественного новообразования яичника лапароскопическим доступом у пациентки после пересадки сердца. Было показано, что лапароскопия представляется технически осуществимым, терапевтически безопасным методом с коротким периодом реабилитации после вмешательства, низким риском инфекционных и послеоперационных осложнений. Применение препарата Флюксум® может быть приемлемой альтернативой использованию других низкомолекулярных гепаринов для профилактики венозных тромбоэмболических осложнений у пациентов высокого риска развития тромбозов. Однако при планировании операции следует учитывать возможность развития осложнений, угрожающих функции трансплантата и жизни больного, и осуществлять пристальное наблюдение таких пациентов в периоперационном периоде.

Heart transplantation has become widespread in world practice lately. Literary data examining algorithms for managing patients after a heart transplant that require surgical intervention is not enough. We have described a clinical case of successful removal of a big benign tumor of the ovary by laparoscopic approach in a patient after a heart transplant. It was shown that laparoscopy seems to be technically feasible, therapeutically safe method with a short period of rehabilitation after the intervention, low risk of infectious and postoperative complications. The use of Fluxum® may be an acceptable alternative to the use of other low molecular weight heparins for the prevention of venous thromboembolic complications in patients at high risk of thrombosis. However, when planning an operation, consideration should be given to the possibility of developing complications that threaten the function of the transplant and the life of the patient, and to closely monitor patients in the perioperative period.
Compliance to antithrombotic therapy in elderly and senile patients with atrial fibrillation.
Authors: Хруслов М.В. , Карпенко М.А. , Вавилова Т.В. , Пономарева И.В.
Published: February 2021

Введение. Приверженность к приему антикоагулянтов является одним из ключевых компонентов эффективной профилактики тромбоэмболических осложнений. Цель исследования: оценка комплаентности пациентов пенсионного возраста, которым назначали прямые оральные антикоагулянты (ПОАК) по поводу неклапанной фибрилляции предсердий (ФП), и выяснение причин ее снижения. Материалы и методы. В ходе исследования осуществляли наблюдение за 244 пациентами с неклапанной ФП. В зависимости от вида принимаемых оральных антикоагулянтов все пациенты были разделены на 2 группы: 1я группа 124 человека, которые принимали ПОАК 2я группа 120 человек, которые принимали варфарин и наблюдались в системе централизованного мониторинга международного нормализованного отношения (МНО). Срок наблюдения составил 1 год. Результаты. Через 1 год от момента назначения препаратов назначения врача соблюдали только 22,6 пациентов 1й группы во 2й группе пациентов никто не прекратил прием варфарина, что указывало на более высокую приверженность к терапии. Заключение. Одним из способов повышения качества и безопасности антитромботической терапии у пациентов, принимающих антагонисты витамина К, является внедрение в клиническую практику системы централизованного мониторинга МНО, которая представляет собой новую клиниколабораторную

Introduction. Adherence to anticoagulants is one of the key components of effective prevention of thromboembolic complications. Aim: to assess the compliance of patients of retirement age who were prescribed direct oral anticoagulants (DOACs) for nonvalvular atrial fibrillation (AF), and to determine the reasons for its reduction. Materials and methods. We monitored 244 patients with nonvalvular AF that were divided into 2 groups: Group 1 124 patients who took DOACs Group 2 120 patients who took warfarin and were observed in the system of centralized monitoring of international normalized ratio (INR). The observation period was 1 year. Results. After 1 year from the moment of drugs prescribing only 22.6 of patients from Group 1 followed the prescription no one patient from Group 2 stopped taking warfarin that indicated a higher adherence to therapy. Conclusion. One of the ways to improve the quality and safety of antithrombotic therapy in patients taking vitamin K antagonists is to introduce into the clinical practice a system of centralized monitoring of INR that is a new clinical and laboratory model of remote interaction between patient and medical specialist.
Results of high-altitude climate treatment of immune thrombocytopenia in children in the Kyrgyz Republic (five-year analysis)
Authors: Эсенгелди А.К.
Published: February 2021

Введение: Вопрос о дальнейшем совершенствовании базисной терапии иммунной тромбоцитопении (ИТП) по-прежнему широко обсуждается специалистами и является предметом оживленных дискуссий. Цель исследования: оценить эффективность высокогорной климатотерапии при хронической ИТП у детей за 5-летний период наблюдения после ежегодного лечения на высокогорной базе. Материалы и методы: В исследование включено 22 ребенка с хронической ИТП в возрасте от 3 до 14 лет, средний возраст — 6,30 ± 1,02 года, длительность заболевания 2-8 лет. Для лечения детей поднимали на высокогорную базу. Продолжительность лечения в высокогорье составляла 40 дней. Результаты: Из 22 детей, получивших 5 курсов высокогорной климатотерапии, у двоих наблюдали полную ремиссию в виде увеличения тромбоцитов более 100×109/л без кровоточивости. Объективный ответ в виде двукратного увеличения числа тромбоцитов, но менее 100×109/л без кровоточивости установлен у 18 детей, отсутствие эффекта было зарегистрировано у 2 детей. Заключение: Повторные курсы высокогорной климатотерапии способствуют улучшению клинической картины, существенному повышению числа тромбоцитов в периферической крови и достижению ремиссии при ИТП у детей.

Background: Further development of basic treatment of immune thrombocytopenia (ITP) is still widely discussed by specialists and is the subject of lively discussions. Objectives: to assess the effi ciency of high-altitude climatotherapy in children with chronic ITP for a 5-year follow-up period after annual treatment at high-altitude base. Patients/Methods: The study included 22 children with chronic ITP from 3 to 14 years, the average age was 6.30 ± 1.02 years, and disease duration was 3-8 years. Children were raised to high-altitude base. Treatment duration was 40 days. Results: 22 children received 5 courses of high-altitude climatotherapy. Complete remission was observed in 2 patients with increasing of platelets more than 100×109/L without bleeding. In 18 children an objective response was found in the form of twofold increasing of platelets number, but less than 100×109/L without bleeding; no effect was recorded in 2 children. Conclusions: Repeated courses of high-altitude climatotherapy improve clinical characteristics, significantly increase the number of platelets in the peripheral blood and contribute to remission in children with ITP.
Anticoagulant management for pregnant women with coronavirus infection
Authors: Лапина И.А. , Доброхотова Ю.Э. , Таранов В.В. , Чирвон Т.Г.
Published: February 2021

Введение. Частота распространения новой коронавирусной инфекции COVID-19 (НКИ COVID-19) среди беременных сравнима с общепопуляционными показателями, что требует особого внимания в связи с повышенным риском материнской смертности в результате осложнений инфекционного процесса. Учитывая наличие гиперкоагуляционного статуса во время физиологически протекающей беременности, инфицирование вирусом COVID-19 может способствовать еще большему усилению прокоагулянтных свой ств крови. Патогенетически обоснованным является применение антикоагулянтной терапии во время беременности при условии верифицированной коронавирусной инфекции с целью снижения риска развития тромботических осложнений. Материалы и методы. Представлены 2 клинических случая успешного применения антикоагулянтов (низкомолекулярного гепарина) у беременных с подтвержденным инфицированием COVID-19. Результаты. Ретроспективный анализ лабораторных и клинических данных продемонстрировал эффективность парнапарина натрия в качестве средства профилактики тромботических осложнений у беременных с НКИ COVID-19. Заключение. Применение антикоагулянтной терапии у беременных с НКИ COVID-19 позволяет снизить риск развития тромботических эпизодов и улучшить репродуктивные исходы беременности.

Background. The COVID-19 frequency among pregnant women is comparable to general population but it requires specific approach due to increased risk of maternal mortality as a result of infectious complications. The hypercoagulation is during physiological pregnancy, and COVID-19 can enhance further a procoagulant conditions. In such cases the anticoagulant therapy is aimed to reduce the thrombotic risk. Patients / Methods. The article presents 2 clinical cases of successful use of anticoagulants (low molecular weight heparin) in pregnant women with confirmed COVID-19. Results. A retrospective analysis of laboratory and clinical data has demonstrated the effi cacy of parnaparin sodium as a means of preventing thrombotic complications in pregnant women with COVID-19. Conclusions. Anticoagulant therapy in pregnant women with COVID-19 allows to reduce the thrombotic risk and improve the reproductive outcomes of pregnancy.
ANALISIS KEMAMPUAN KOGNITIF PESERTA DIDIK DALAM MENYELESAIKAN SOAL MOMENTUM DAN IMPULS
Authors: Nabilah Mona , Sitompul Stepanus Sahala , Hamdani Hamdani
Published: February 2021

This research aims to examine students’ cognitive abilities in completing physics problem about momentum and impulses at SMA Kristen Immanuel Pontianak. The research uses survey method, by giving test that consists of 11th grader (53 male; 69 female). According to the result, it was found that the total average percentage of students’ cognitive abilities in general (C1-C4) was 69% and was categorized as medium. The highest average percentage of student cognitive ability was in the domain remembering (C1) with the percentage of 90% (high) and the lowest was in the domain of analyzing with the percentage of 53% (low). Furthermore, there was difference in students’ cognitive ability based on gender in domain of remembering (C1), that was recognized from the result of Mann-Whitney statistical test (0.004<0.05), which showed that significance value was below the probability value. This research is expected to be a guide and reference in developing learning strategies in physics problem to improve students’ cognitive abilities.Keywords: Analysis, Cognitive, Momentum and Impulses, Gender
INTEGRASI REMEDIASI KESULITAN BELAJAR MENGGUNAKAN MODEL CORE BERBANTUAN BOOKLET TENTANG GETARAN GELOMBANG DI SMP
Authors: Safira Ariza Fitriani , S Haratua Tiur Maria , Mursyid Syukran
Published: February 2021

This research aims to examine the effectiveness of the integrated remediation using booklet-assisted CORE leraning model to reduce students' learning difficulties about vibrations and waves at SMP Negeri 2 Pontianak. The research design is One-Group Pretest-Posttest Design with 27 students in class VIII C as samples using the intact group technique. The instruments are two-tiered multiple choice tests to analyze students’ learning difficulties related to concepts and essay tests to analyze students’ learning difficulties related to errors in solving problems. Based on the results, it is found that: (1) Students’ total misconceptions decreasing by 84.2%. (2) There is a significant conceptual change in all test items. (3) All students’ total errors in solving questions decreased by 78.32% (4) There are significant difference between the number of students' initial and final mistakes. (5) The percentage of all students’ learning difficulties decreased by 78.91%. (6) The remediation integration using CORE model assisted by a booklet has a high effectiveness to reduce students’ learning difficulties. The result of this study is expected to be a consideration for teachers in designing learning difficulties’ remediation activities for students, especially about vibrations and waves.Keywords: CORE Learning Model, Booklet, Students’ Learning Difficulties, Vibration and Waves
PENERAPAN MODEL PEMBELAJARAN DISCOVERY LEARNING TERHADAP KETERAMPILAN PROSES SAINS SISWA PADA MATERI LISTRIK DINAMIS DI KELAS IX SMP NEGERI 7 SUNGAI RAYA
Authors: Arlisa Arlisa , Saputri Dewi Fajar , Boisandi Boisandi
Published: February 2021

This study aims to obtain an objective clarity regarding the application of discovery learning models to students' science process skills in dynamic electrical material for class IX students of SMP Negeri 7 Sungai Raya. This research method uses the Quasi Experiment Design method with the research design is Posttest-Only Nonequivalent Groups. Data collection techniques are essay tests to measure students' science process skills. The population in this study were all grade IX students of SMP Negeri 7 Sungai Raya consisting of 4 classes. The sample in this study were students of SMP Negeri 7 Sungai Raya in class IX B and class IX C in the odd semester of the 2019/2020 school year, taken by cluster random sampling. Analysis of the data description using the average equation (mean), analysis of the hypothesis test using the U Maan Whitney test. The results of this study indicate that 1) the students' science process skills after applying the direct learning model to the dynamic electrical material of class IX students of SMP Negeri 7 Sungai Raya is classified as not good at 62.67; 2) students' science process skills after the discovery learning model applied to the dynamic electrical material of class IX students of SMP Negeri 7 Sungai Raya is classified as good, amounting to 81.07; 3) there are differences in the science process skills of students who are taught using discovery learning models and students who are taught using direct learning models on dynamic electrical material for class IX students of SMP Negeri 7 Sungai Raya.Keywords: Student Science Process Skills, Discovery Learning
PENGEMBANGAN TES DIAGNOSTIK UNTUK MENGIDENTIFIKASI MISKONSEPSI HUKUM ARCHIMEDES KELAS VIII SMP DI KUBU RAYA
Authors: Sari Dhiya Ratna , Sitompul Stepanus Sahala , Mursyid Syukran
Published: February 2021

This study aims to produce a multiple choice diagnostic test on the Archimedes Law to identify misconceptions of junior high school students in Kubu Raya Regency. The method used in this research is Research and Development (R&D). The test development steps used are the Borg and Gall development steps which consist of 7 steps. The test consisted of 30 multiple choice questions accompanied by reasons followed by 28 small-scale test students and 119 students on large-scale test. The characteristics of the diagnostic test used consist of 6 characteristics. The results of the data analysis are appropriate if it is associated with good test characteristics, namely the test is specifically designed to detect misconceptions and developed based on the students' initial conception, the readability level of questions is 4.07 according to junior high school level, has a high validity of 0.75, high reliability of 0.748, and has a level of moderate or low difficulty. From the characteristics of the test, there are 28 questions that can be used. The results of this study are expected to be useful for future researchers as research instruments regarding the Archimedes lawKata Kunci: Diagnostic Test, Archimedes Law, Test Development
An Empirical Study on Lead Time of Readymade Garments in Bangladesh
Authors:   Department of Textile Engineering, National Institute of Textile Engineering and Research (NITER), Bangladesh, A Khan
Published: February 2021

This paper addressed the issues that lead up to the higher lead-time in readymade garment industries of Bangladesh. Lead-time involve the time required to deliver any good to the specified destination since receiving the order. For Bangladesh, usual lead time is 90-120 days which is very high compared to competing countries like China, Vietnam etc. This time span is prolonged by issues such as worker unrest, political instability, poor productivity, poor production planning etc. The aim of this paper was to pin point these factors and explain exactly how these issues increases the lead-time. Another objective of this study was to propose realistic solutions to the stated lead time problem. This study was conducted with a combination of quantitative and qualitative approaches. The factors working behind higher lead time and the proposed solutions are being suggested by industry experts working in the supply chain management sector. This study was conducted with hope to help the supply chain professionals working in the readymade garment industries in reducing lead-time by various SCM strategies.
SVECV-f12: benchmark of a composite scheme for accurate and cost effective evaluation of reaction barriers.
Authors: Ventura Oscar , Kieninger Martina , Katz Aline , Vega-Teijido Mauricio , Segovia Marc E. , Irving Kenneth
Published: February 2021

A simple composite scheme is presented, based on a combination of density functional geometry and frequencies evaluation, valence energies obtained using the CCSD(T)-f12 method extrapolated to the complete basis set limit, and core-valence correlation corrections employing the MP2 method. The procedure was applied to the 38 reactions in Truhlar’s HTBH38/08 and NHTBH38/08 databases and the errors in the barriers with respect to their best values are presented. Mean unsigned deviation (MUD) for the complete set of 68 independent barriers is 0.40 kcal mol-1 , compared to 1.31 kcal/mol for G4 and 1.62 kcal/mol for the dispersion-corrected M06- 2X method. The accuracy of the procedure is also better that that of other calculations using composite methods of similar cost. The MUD of the new scheme on the barriers in the DBH24/08 subset (12 out of the 38 reactions in the other two sets) is 0.27 kcal mol-1 , better than that obtained at the expensive CCSD(T,full)/aug-cc-pCV(T+d)Z level (0.46 kcal mol-1 ) and comparable to the 2 most exact (and costly) Wn calculations (MUD=0.14 kcal mol-1 ). The maximum unsigned deviation (MaxUD) for all the reactions studied is 0.99 kcal/mol. G4 and M06-2X, on the other side, exhibit MaxUDs of 6.7 and 8.0 kcal/mol respectively. The method was further tested against a subset of the reactions in the databases, for which the geometry and energies of all species were determined at the much more demanding CCSD(T)-F12//pVQZ-F12 level. These results showed that Truhlar’s calculations in this subset are off the best values by a considerable amount, with an rmse of 0.56 kcal/mol. As a consequence, a new dataset of barrier heights, SV20, is presented. The SVECV-F12 procedure on this SV20 database results in rmse and MUD values of only 0.21 and 0.16 kcal/mol. The possible residual errors introduced by the approximations used for each component of the method are tested against more sophisticated calculations and shown to be accurate enough to obtain barriers well under the chemical precision limit at a reasonable cost for molecules of interest in atmospheric chemistry.
The Stabilizing Effect of Pre-Equilibria: A Trifluoromethyl Complex as CF2 Reservoir in Catalytic Olefin Difluorocarbenation
Authors: Louis-Goff Thomas , Trinh Huu Vinh , Chen Eileen , Rheingold Arnold L. , Ehm Christian , Hyvl Jakub
Published: February 2021

A new, efficient, catalytic difluorocarbenation of olefins to give 1,1-difluorocyclopropanes is presented. The catalyst, an organobismuth complex, uses TMSCF3 as a stoichiometric difluorocarbene source. We demonstrate both the viability and robustness of this reaction over a wide range of alkenes and alkynes, including electron-poor alkenes, to generate the corresponding 1,1-difluorocyclopropanes and 1,1-difluorocyclopropenes. Ease of catalyst recovery from the reaction mixture is another attractive feature of this method. In depth experimental and theoretical studies showed that the key difluorocarbene-generating step proceeds through a bismuth non-redox synchronous mechanism generating a highly reactive free CF2 in an endergonic pre-equilibrium. It is the reversibility when generating the difluorocarbene that accounts for the high selectivity, while minimizing CF2-recombination side-reactions.
A Natural Rubber Waste Derived Surfactant for High Internal Phase Emulsion Templating of Poly(dicyclopentadiene)
Authors: Schallert Viktor , Slugovc Christian
Published: February 2021

The use of a surfactant derived from the degradation of natural rubber gloves via cross-metathesis with methyl acrylate and subsequent saponification of the ester group for the stabilization of water in dicyclopentadiene high internal phase emulsions is described. The versatility of the resulting high internal phase emulsion was demonstrated by polymerizing the continuous dicyclopentadiene phase via Ring-opening Metathesis Polymerization yielding macroporous poly(dicyclopentadiene) foams with a porosity of 82 %. The use of the ionic surfactant allows for the preparation of foams, which are resistant to absorb water. This property was hitherto not accessible with protocols involving the use of non-ionic surfactants commonly employed in emulsion templating of polymers.
Identification of the Core Chemical Structure in SureChEMBL Patents
Authors: Falaguera Maria J. , Mestres Jordi
Published: February 2021

The SureChEMBL database provides open access to 17 million chemical entities mentioned in 14 million patents published since 1970. However, alongside with molecules covered by patent claims, the database is full of starting materials and intermediate products of little pharmacological relevance. Herein, we introduce a new filtering protocol to automatically select the core chemical structures best representing a congeneric series of pharmacologically relevant molecules in patents. The protocol is first validated against a selection of 890 SureChEMBL patents for which a total of 51,738 manually curated molecules are deposited in ChEMBL. Our protocol was able to select 92.5% of the molecules in ChEMBL from all 270,968 molecules in SureChEMBL for those patents. Subsequently, the protocol was applied to all 240,988 US pharmacological patents for which 9,111,706 molecules are available in SureChEMBL. The unsupervised filtering process selected 5,949,214 molecules (65.3% of the total number of molecules) that form highly congeneric chemical series in 188,795 of those patents (78.3% of the total number of patents).
Outstanding Nobility Observed in Cu5 Clusters Reveals the Key Role of Collective Quantum Effects
Authors: Buceta David , Huseyinova Shahana , Cuerva Miguel , Lozano Héctor , Giovanetti Lisandro J. , Ramallo-López José M. , López-Caballero Patricia , Zanchet Alexandre , Mitrushchenkov Alexander O. , Hauser Andreas W. , Barone Giampaolo , Huck-Iriart Cristián , Escudero Carlos , Hernández-Garrido Juan Carlos , Calvino José , Lopez-Haro Miguel , de Lara-Castells Maria Pilar , Requejo Felix G. , López-Quintela M. Arturo
Published: February 2021

Subnanometer-sized metal clusters often feature a molecule-like electronic structure, which makes their physical and chemical properties significantly different from those of nanoparticles and bulk material. Considering potential applications, there is a major concern about their thermal stability and susceptibility towards oxidation. Cu clusters of only 5 atoms (Cu5 clusters) are first synthesized in high concentration using a new-generation wet chemical method. Next, it is shown that, contrary to what is currently assumed, Cu5 clusters display nobility, beyond resistance to irreversible oxidation, at a broad range of temperatures and oxygen pressures. The outstanding nobility arises from an unusual reversible oxidation which is observed by in situ X-ray Absorption Spectroscopy and X-ray Photoelectron Spectroscopy on Cu5 clusters deposited onto highly oriented pyrolitic graphite at different oxygen pressures and up to 773 K. This atypical property is explained by a theoretical approach combining different state-of-the-art first principles theories. It reveals the essential role of collective quantum effects in the physical mechanism responsible for the nobility of Cu5 clusters, encompassing a structural ‘breathing’ through concerted Cu–Cu elongations/contractions upon O2 uptake/release, and collective charge transfer as well. A predictive phase diagram of their reversible oxidation states is also delivered, agreeing with the experimental observations. The collective quantum effects responsible of the observed nobility are expected to be general in subnanometer-sized metal clusters, pushing this new generation of materials to an upper level.
BioAIEgens Derived from Rosin: How Does Molecular Motion Affect Their Photophysical Processes in Solid State?
Authors: Cai Xu-Min , Lin Yuting , Li Ying , Chen Xinfei , Wang Zaiyu , ZHAO Xueqian , Huang Shenlin , Zhao Zheng , Tang Ben Zhong
Published: February 2021

The exploration of artificial luminogens with bright emission has been fully developed with the advancement of synthetic chemistry. However, many of them face problems like weakened emission in the aggregated state as well as poor renewability and sustainability. Therefore, the development of renewable and sustainable luminogens with anti-quenching function in the solid state, as well as to unveil the key factors that influence their luminescence behavior become highly significant. Herein, a new class of natural rosin-derived luminogens with aggregation-induced emission property (AIEgens) have been facilely obtained with good biocompatibility and targeted organelle imaging capability as well as photochromic behavior in the solid state. Mechanistic study indicates that the introduction of the alicyclic moiety helps suppress the excited-state molecular motion to enhance the solid-state emission. The current work fundamentally elucidates the role of alicyclic moiety in luminogen design and practically demonstrates a new source to large-scalely obtain biocompatible AIEgens.
Engineered Jute Bags for Storing Food Grains within Harrington’s Safe Zone of Seed Moisture Content
Authors: Odokonyero Kennedy , Mishra Himanshu , Junior Adair Gallo
Published: February 2021

Harrington’s thumb rule states that for every 1% increase in seed moisture content (SMC), seed lifetime decreases by 50%. Thus, to avoid post-harvest grain losses, stored seeds must be insulated from water. Although the jute bags typically used to store grains afford an ecofriendly, durable, and low-cost storage solution, their hydrophilic nature makes them vulnerable to wetting from airborne humidity and precipitation events. To address this issue, we treated jute fabrics with alkali and wax to render them water-repellent. A 2-month seed storage experiment revealed that wax-coated jute bags (WCJBs) outperformed control jute bags (CJBs) at safeguarding wheat (Triticum aestivum) grains exposed to 55%–98% relative humidity. Specifically, grains stored in WCJBs exhibited 15%–50% less SMC than grains stored in CJBs, which led to a 21%–66% enhancement in the germination efficacy of WCJB-stored seeds. This engineering solution could enhance the potential of jute bags to reduce post-harvest losses.
Studies of Catalyst-Controlled Regioselective Acetalization and Its Application to Single-Pot Synthesis of Differentially Protected Saccharides.
Authors: Lee Jeonghyo , Wang Sibin , Zhelavskyi Oleksii , Arguelles Alonso J. , Mensah Enoch A. , Guo Hao , Hourani Rami , Zimmerman Paul M. , Nagorny Pavel
Published: February 2021

This article describes the studies of regioselective acetal protection of monosaccharide-based diols using chiral phosphoric acids (CPAs) as the catalysts. These catalyst-controlled regioselective acetalizations were found to proceed with high regioselectivities (up to >25:1 rr) on various D-glucose, D-galactose, D-mannose and L-fucose derived 1,2-diols and could be carried with immobilized and recyclable catalyst. The utility of CPA-catalyzed acetalizations was further demonstrated for the regioselective single-pot preparation of various differentially protected mono- and disaccharide building blocks. The computational and mechanistic studies indicate complex temperature-dependent interplay of two reaction mechanisms, one involving an anomeric phosphate intermediate and another via concerted asynchronous formation of acetal. The computational models explain the steric factors responsible for the observed C2-selectivities and are consistent with the experimentally observed selectivity trends.
Mechanism of 8-Aminoquinoline Directed Ni-Catalyzed C(sp3)-H Functionalization: Paramagnetic Ni(II) Species, and the Deleterious Effect of Na2CO3 as a Base
Authors: Liu Junyang , Johnson Samuel
Published: February 2021

Studies into the mechanism of 8-aminoquinoline-directed nickel-catalyzed C(sp3)–H arylation with iodoarenes are described, in attempts to determine the catalyst resting state and optimize catalytic performance. Paramagnetic complexes are identified that are undergo the key C–H activation step. Hammett analysis using electronically different aryl iodides suggests a concerted oxidative addition mechanism for the C–H functionalization step; DFT calculations were also performed to support this finding. When Na2CO3 is used as the base the rate determination step for C–H functionalization appears to be 8-aminoquinoline deprotonation and binding to Ni. The carbonate anion was also observed to provide a deleterious NMR inactive low-energy off-cycle resting state in catalysis. Replacement of Na2CO3 with NaOtBu not only improved catalysis at milder conditions but also eliminated the need for carboxylic acid and phosphine additives.
Communication of Knowledge
Authors: Prescott Steven
Published: February 2021

N/A
IRB Reform in North America: Challenges and Opportunities
Authors: Zettler Marjorie Ellen
Published: February 2021

Clinical research is necessary to advance medical knowledge and to test new drugs or devices. It is therefore vital to society, and ethically imperative, that clinical studies be performed if patients are to have access to safe and effective treatments. However, clinical research by its very nature involves risk. Subjects who volunteer in clinical studies may receive no benefit; in fact, they may be seriously harmed or even die as a result of their participation. Indeed, research-related injuries and deaths, though relatively few in number (1), have become the subject of much controversy in recent years (2). Thus, the protection of human research subjects must be given the highest priority by researchers, their institutions, and the government and regulatory bodies charged with overseeing the clinical research process. Central to this process is the institutional review board (IRB) in the United States (U.S.), or research ethics board as it is known in Canada. (For the purpose of this paper, the term "IRB" will be used to refer to both American and Canadian boards.) The IRB has frequently been referred to as the "first line of defense" in research subject protection (3), yet the specific roles and responsibilities of this board and its members are not clear (4). Defining these roles and responsibilities is more important now than ever before, for several reasons.
The History of Trauma Care Systems From Homer to Telemedicine
Authors: Liberman Moishe , Mulder David S. , Sampalis John S.
Published: February 2021

N/A
Domestic Animal Welfare at the Zoo: The Impact of an Animal Visitor Interaction Program on Chickens
Authors: Ramont Margaret , Leahy Maureen , Cronin Katherine A.
Published: February 2021

Many modern zoos strive to create connections between guests and animals through animal visitor interaction (AVI) programs. However, there has been relatively little research into the effect of AVI programs on the welfare of program animals. Previous research has revealed three factors that may affect AVI program animal welfare: species differences, handling and transport, and the provision of choice and control. We assessed the effects of an AVI program designed with these factors in mind on the behavior of a flock (N = 16) of zoo-housed domestic chickens (Gallus gallus). Behavioral data were collected on program days and on non-program (control) days, and we considered the time leading up to the program, the program itself, and the time immediately following the program. When comparing flock behavior on program days to control days, we found no differences in behavioral indicators of welfare during the time leading up to the program and during the program. Rates of aggression, however, were significantly greater after the program had concluded compared to the same time period on matched control days, but still occurred infrequently. Additionally, we recorded the spatial location of each animal while the program occurred and found that the chickens did not spend significantly more or less time in the feeding zone as visitor participation increased, although there were individual differences within the flock. We conclude that the relatively small behavioral changes seen were not indicative of a change in welfare and consider those results in the context of the program design.