bluuebunny/crossref_metadata_2025 huggingface dataset:
Intravenous thrombolytic therapy for acute ischemic stroke in Hubei, China: a survey of thrombolysis rate and barriers
Authors: Zhou Yanfeng , Yan Shijiao , Song Xingyue , Gong Yanhong , Li Wenzhen , Wang Mengdie , Yin Xiaoxv , Hu Bo , Lu Zuxun
Published: January 2019

Background: Rates of thrombolysis in most countries are well below best practice benchmarks. We aimed to investigate thrombolysis utilization and its associated factors in acute ischemic stroke (AIS) patients in Hubei province, China, to assess neurologists’ experiences of the treatment, and to identify barriers against the treatment from perspective of AIS patients and neurologists.
Methods: Survey of 2096 AIS patients and 709 neurologists from 66 hospitals was conducted in Hubei province between 2014 and 2015. A multivariable logistic regression model was utilized to identify the factors associated with thrombolysis utilization and neurologists’ experiences with thrombolysis.
Results: Of the 2096 AIS patients, only 3.8% received thrombolysis. Of the 709 neurologists, 66.0% reported using thrombolysis for AIS patients. The main reasons for not using thrombolysis were late arrival of patients, fear of the risk of complications of thrombolysis, and light or quickly recovered stroke symptoms. The behavior and clinical characteristics of patients, including early admission to hospital (odds ratio [OR]=5.81, 95% confidence intervals [CI] 3.31-10.20), using emergency medical services to be hospitalized (OR=3.36, 95% CI 2.00-5.62), stroke history (OR=0.53, 95% CI 0.28-0.99), and National Institute of Health Stroke Scale score < 4 (OR=0.46, 95% CI 0.27-0.77) were shown to significantly affect the thrombolysis utilization in the multivariate model. In addition, hospital grade (OR=2.84, 95% CI 1.84-4.37), education level (OR=2.49, 95% CI 1.09-5.73), and working years (OR=1.88, 95% CI 1.18-3.00) were strongly associated with neurologists’ experiences of thrombolysis.
Conclusions: A very low proportion of AIS patients received thrombolysis in Hubei province, China. Considerable education programs and interventions were required regarding knowledge of stroke treatment for clinicians and proper behavior after stroke for AIS patients and their families.
Keywords: Thrombolysis; stroke; neurologists; emergency medical services; China; Risk factor.
The central mechanism of tadalafil vs Chaihu-Shugan-San capsule for psychogenic erectile dysfunction: a magnetic resonance imaging study protocol of a randomized placebo-controlled trial
Authors: Ren Feiqiang , Ma Ziyang , Zhang Ling , Dong Liang , Chen Diang , Chang Degui , Zhang Peihai , Li Guangsen , Huang Xiaopeng , You Yaodong , Yu Xunjun , Yang Fang , Li Zhengjie
Published: January 2019

Background: Erectile dysfunction (ED) affects many adult men worldwide. Many studies on the brain of psychogenic ED have shown significant cerebral functional changes and reduced volume of gray matter and white matter microstructural alterations in widespread brain regions. We design this study to provide both an enhanced level of evidence of central mechanism research and an evidence-based treatment option for patients suffering from psychogenic ED. Furthermore, we also aim to provide a new evidence as well as an innovation of the clinical treatment in psychogenic ED.
Methods: This study is designed as a multi-center, three-arms, randomized trial. From the perspective of psychogenic ED, we will divide patients into three groups, which are placebo group, tadalafil group and CHSGS group. 135 patients will be randomly allocated to receive placebo, CHSGS capsule or tadalafil oral pharmacotherapy. After the period of 4-week treatment, the outcome of primary assessment changes in the IIEF-5, EHS and QEQ total scores from baseline. Secondary assessments include the SEAR, HAMA-14, HAMD-17 scores, response rate of the patients and their partners. Apart from brain MRI from baseline, we will also attach great importance to other changes in the follow-up four weeks.
Discussion: We expect that the results of this trial can provide both an enhanced level of evidence for central mechanism research and an evidence-based treatment option for patients suffering from ED, as well as to provide an innovation of the clinical treatment in psychogenic ED.
Trial Registration: chictr.org.cn, ChiCTR-IOR-1800018301. Registered on 10 September 2018.
Keywords: Erectile dysfunction, psychogenic ED, MRI, Randomized controlled trial.
Physical Activity In Renal Disease (PAIRED) and the effect on hypertension: study protocol for a randomized controlled trial
Authors: Thompson MD Stephanie , Wiebe MMath/PStat Natasha , Gyenes MD Gabor , Davies MSc Rachelle , Radhakrishnan Jeyasundar , Graham MD Michelle
Published: January 2019

Background: The prevalence of hypertension among people with chronic kidney disease is high with over 60% of people not attaining recommended targets despite multiple medications. Given the health and economic implications of hypertension, additional strategies are needed. Exercise is an effective strategy for reducing blood pressure in the general population; however, it is not known whether exercise would have a comparable benefit in people with moderate to advanced chronic kidney disease and hypertension.
Methods: This is a parallel arm trial of adults with hypertension (systolic blood pressure greater than 130 mmHg) and an estimated glomerular filtration rate of 15-45 ml/min 1.73 m2. A total of 160 participants will be randomized, with stratification for estimated glomerular filtration rate, to a 24-week aerobic-based exercise intervention or enhanced usual care. The primary outcome is the difference in 24-hour ambulatory systolic blood pressure after eight weeks of exercise training. Secondary outcomes at eight and 24 weeks include: other measurements of blood pressure, aortic stiffness (pulse wave velocity), change in the Defined Daily Dose of anti-hypertensives, medication adherence, markers of cardiovascular risk, physical fitness (cardiopulmonary exercise testing), seven day accelerometry, quality of life, and adverse events. The effect of exercise on renal function will be evaluated in an exploratory analysis. The intervention is a thrice-weekly moderate intensity aerobic exercise supplemented with isometric resistance exercise delivered in two phases. Phase 1: supervised, facility-based weekly and home-based sessions (eight weeks). Phase 2: home-based sessions (16 weeks).
Discussion: To our knowledge, this study is the first trial designed to provide a precise estimate of the effect of exercise on blood-pressure in people with moderate to severe CKD and hypertension. The findings from this study will address a significant knowledge gap in hypertension management in CKD and inform the design of a larger study on the effect of exercise on CKD progression.
Trial registration: Registered at ClinicalTrials.gov NCT03551119. Registered on 11 June 2018.
Determination of anticancer effects of Urospermum picroides against human cancer cell lines
Authors: ALPER Mehlika , GÜNEŞ Hatice
Published: January 2019

Plants continue to be a
good source for developing effective anticancer agents. In this study, in
vitro various biological effects of crude ethanolic extract from flowering
parts of Urospermum picroides
collected from the Muğla province of Turkey were investigated for the first
time.
Daudi, A549 and HeLa cancer cell lines and BEAS-2B normal cell line were used
to identify
the cytotoxic effect of the extract using MTT assay. The effect of the extract
on cell cycle progression was detected by flow
cytometric analysis. The
level of VEGF, IL-1α, IL-6 and TNF-α secretion in the cells treated with the
extract were measured using ELISA The extract caused a higher cytotoxic effect
on Daudi cells with an IC50 value of 85.64 µg/mL than the
other cells tested. The IC50 values in HeLa and A549 cells were determined to be 135.35 and 234.8 µg/ mL, respectively. The selective
cytotoxicity was considered between Daudi and BEAS-2B (109.80 µg/mL) cell
lines. In addition, the effect of the extract on cell cycle progression changes
according to cell line used. Moreover, the extract decreased the level of
secreted VEGF in treated A549 cells by 31%. In addition, the extract resulted
in a significant decrease in the secretion of IL-1α, IL-6 and TNF-α cytokines
in A549 and Daudi cells compared to the untreated cells. These findings suggest
that the flowering parts of U. picroides may be a potential source for
anticancer agents.
TÜRK SOSYOLOJİ CEMİYETİ’NİN RESMİ DERGİSİ: SOSYOLOJİ DÜNYASI
Authors: FİLDİŞ Berna
Published: January 2019

Türk Sosyoloji Cemiyeti (TSC) Aralık 1949’da,
aynı yılın Eylül ayında Oslo’da düzenlenen bir toplantıyla faaliyete geçen Uluslararası
Sosyoloji Cemiyeti’nin Türkiye ayağı olarak kurulmuştur. Üyeleri arasında İdare
Heyeti Başkanlığı’nı yürüten Hilmi Ziya Ülken’in yanı sıra Ziyaeddin Fahri
Fındıkoğlu, Nurettin Şazi Kösemihal, Cahit Tanyol ve Nezahat Nurettin Ege gibi
isimler bulunmaktadır. TSC, öncelikli gördüğü ‘mecmua neşretmek’ amacı
çerçevesinde Sosyoloji Dünyası isminde bir resmi yayın organına sahip olmuştur.
1951-1953 yılları arasında üç sayı çıkan dergi, sosyoloji alanında yürütülen
yazı faaliyetleri açısından dönemin önemli adreslerindendir. Makalemizde,
Sosyoloji Dünyası’nın üç sayısında yer alan toplam 42 yazı incelenerek derginin
mahiyeti ve dönem itibariyle yerli sosyoloji camiasında konumlandığı yer anlaşılmaya
çalışılmıştır.
Território da mineração: uma contribuição teórica
Authors: Espindola Haruf Salmen , Ferreira Natália Moreira , Mifarreg Iesmy Elisa Gomes
Published: January 2019

O território da mineração no Brasil ganhou destaque com o desastre de 5 de novembro de 2015, desencadeado pelo rompimento da barragem da Samarco Mineração, na bacia do Rio Doce. Os eventos fizeram emergir a existência do complexo minero-metalúrgico e os riscos, principalmente para populações mais frágeis (comunidades rurais negras e mestiças, indígenas, ribeirinhos pobres, agricultores e pescadores). O artigo examina a questão pelo conceito de envirotechnical de Sara Pritchard, historiadora ambiental. A definição de espaço geográfico proposta por Milton Santos foi ampliada pela introdução dos conceitos de biocultura, território e multiterritorialidade. A combinação dos conceitos possibilitou considerar as heterogeneidades socioespaciais e ecossistêmicas, de modo a fazer emergir o cerne do fenômeno criado pela presença do complexo minerador: as contradições como relacionalidades marcadas pelo poder.
ЭКСПЕРИМЕНТАЛЬНЫЕ МОЛЕКУЛЯРНЫЕ МЕХАНИЗМЫ ДЕЙСТВИЯ АНТИОКСИДАНТОВ НА ЛИПИДНЫЙ КОМПОНЕНТ КЛЕТОК МОЗГА ПРИ ВНУТРИУТРОБНОЙ ГИПОКСИИ ПЛОДА
Authors:   Ташкентский педиатрический медицинский институт, З.Р. Хайбуллина , Г.Г. Сулейманова , Г.А. Ихтиярова , Ф.Ш. Орипова ,   Республиканский специализированный научно-практический медицинский центр хирургии им. ак. В. Вахидова,   Бухарский медицинский институт Узбекистан
Published: January 2019

Fetal hypoxia is the leading cause of neonatal mortality and morbidity. The modern view on the problems of fetal hypoxia is that an insignificant effect of oxygen deficiency in the early phase of intrauterine development has been established, while hypoxia during organogenesis in the 2nd and 3rd trimesters of pregnancy can cause fatal consequences.
RUNTUHNYA DIKOTOMI TRADISIONALIS DAN MODERNIS: MENILIK DINAMIKA SEJARAH NAHDATUL ULAMA DAN MUHAMMADIAYAH
Authors: Istoria Admin Wisnu
Published: January 2019

Abstrak NU tradisional dan Muhammadiyah modern adalah pandangan yang sudah umum dikemukakan. Tradisional karena dalam praktek keagamaan, kalangan NU hanya mengikuti pendapat dan menjalankan praktek keagamaan para ulama terdahulu, sehingga yang ada hanyalah taklid dan menolak ijtidah. Demikian pula, ketradisionalan NU biasanya dituduhkan karena banyak praktek ritual yang dicampuradukan oleh kalangan ini dengan budaya-budaya yang sudah ada. Sebaliknya, Muhammadiyah terkenal modern karena golongan ini mencoba membawa Islam agar sesuai dengan tuntutan dan keadaan zaman. Menurut kalangan Muhammadiyah, Islam juga berarti kemajuan sementara agama tidak akan menghambat siapapun yang berusaha untuk mencari ilmu pengetahuan. Namun, dalam perjalanan sejarah, tampaknya dikotomi semacam ini perlu dipertanyakan kembali. Kenyataan membuktikan bahwa untuk konteks sekarang ternyata sulit untuk mengatakan bahwa NU tradisional, terutama dalam hal pemikiran keagamaan. Dapat dilihat, konsep seperti inklusif, substansial, konvergen, manhaji, dan bahkan liberal, yang sekarang ini sering diusung dan disuarakan di kalangan NU adalah manifestasi dari pemikiran modern. Berpikir kritis sebagai salah satu ciri modern, tampaknya telah dikonsumsi, sehingga wajar apabila di kalangan NU sekarang ini muncul istilah ”pemaknaan ulang ahlus Sunnah Waljamaah” dan ”pemaknaan ulang konsep bermazdhab”. Yang nyata, dalam segala hal praktek keagamaan dan pemikiran keagamaan, menurut kalangan NU ini, boleh dipertanyakan kembali dan bahkan digugat. Kata Kunci: Berpikir kritis, dikotomi, modern, Muhammadiyah, NU, pemaknaan ulang, dan tradisional.
Peningkatan Kualitas Pembelajaran dengan Model Pembelajaran Cooperative Learning
Authors: Lestari Barkah
Published: January 2019

Penelitian ini bertujuan untuk mengetahui peningkatan kualitas pembelajaran dengan model pembelajaran cooperative learning dalam matakuliah Evaluasi Pembelajaran Ekonomi pada mahasiswa Program Studi Pendidikan Ekonomi Koperasi, Pendidikan Dunia Usaha, Fakultas Ilmu Sosial Universitas Negeri Yogyakarta. Jenis penelitian ini adalah penelitian tindakan partisipan. Setting penelitian adalah Program Studi Pendidikan Ekonomi Koperasi, Pendidikan Dunia Usaha, Fakultas Ilmu Sosial, Universitas Negeri Yogyakarta. Penelitian ini dilaksanakan pada semester ganjil 2004/2005, untuk Mata kuliah Evaluasi Pembelajaran Ekonomi. Penelitian tindakan ini dilakukan melalui beberapa tahapan yaitu : tahap perencanaan, implementasi tindakan, pemantauan dan hasil serta evaluasi dan  refleksi. Analisis data secara deskreptif kuantitatif. Dari data yang terkumpul  selanjutnya diklasifikasikan dan dikategorikan secara sistematik dan menurut karakteristiknya. Hasil penelitian menunjukkan bahwa (1) model pembelajaran dengan model cooperative learning dapat meningkatkan kualitas pembelajaran, baik dilihat dari tingkat partisipasi, interaksi pembelajaran, hasil kuis dan tes, serta hasil tugas kerja kelompok, (2) Secara umum mahasiswa menyukai model pembelajaran cooperative learning karena dianggap memberikan banyak manfaat.
Penerapan Problem-Based Learning dalam Pembelajaran Statistika Lanjut
Authors: Muhson Ali
Published: January 2019

Pengembangan metode pembelajaran semakin penting untuk terus digalakkan agar efektivitas pembelajaran semakin meningkat. Penelitian ini berupaya untuk menerapkan metode pembelajaran Problem-Based Learning untuk mata kuliah Statistika Lanjut guna melihat dampaknya terhadap peningkatan minat belajar dan pemahaman mahasiswa. Penelitian ini dilakukan dengan menerapkan model penelitian tindakan kelas (Classroom Action Research) yang terdiri atas empat tahap yaitu perencanaan, implementasi, pemantauan, serta evaluasi dan refleksi. Penelitian ini menemukan bahwa (1) penerapan metode Problem Based Learning dalam pembelajaran statistika lanjut mampu meningkatkan minat belajar mahasiswa baik minat belajar di dalam maupun di luar kelas hal ini terjadi karena proses pembelajaran lebih banyak diberikan penugasan analisis kasus baik secara individual maupun kelompok sehingga menuntut partisipasi semua mahasiswa dalam proses pembelajaran, dan (2) penerapan metode Problem Based Learning dalam pembelajaran statistika lanjut mampu meningkatkan pemahaman mahasiswa karena proses pembelajaran lebih ditekankan pada penerapan teknik dan prosedur statistika sehingga memudahkan mahasiswa untuk memahami konsep dan penerapannya.
IMPLEMENTASI MODEL PEMBELAJARAN KOOPERATIF TIPE THINK PAIR SHARE UNTUK MENINGKATKAN AKTIVITAS BELAJAR AKUNTANSI SISWA KELAS XI IPS 1 SMA NEGERI 2 WONOSARI TAHUN AJARAN 2011/2012
Authors: Kusuma Febrian Widya , Aisyah Mimin Nur
Published: January 2019

Penelitian ini bertujuan untuk meningkatkan aktivitas belajar Akuntansi danmengetahui respons siswa terhadap implementasi model pembelajaran kooperatif tipe ThinkPair Share pada siswa kelas XI IPS 1 SMA Negeri 2 Wonosari tahun ajaran 2011/2012.Jenis penelitian ini adalah Penelitian Tindakan Kelas yang dilaksanakan dalam duasiklus dengan subjek penelitian kelas XI IPS 1 SMA Negeri 2 Wonosari tahun ajaran2011/2012 yang berjumlah 33 siswa. Teknik pengumpulan data yang digunakan adalahobservasi, dokumentasi, wawancara, dan angket. Analisis data yang digunakan antara lainanalisis data kualitatif, yakni reduksi data, penyajian data, dan penyimpulan, serta analisisdata kuantitatif yakni penilaian aktivitas belajar Akuntansi dan respons siswa terhadapimplementasi pembelajaran Think Pair Share.Berdasarkan hasil penelitian dapat disimpulkan bahwa terjadi peningkatan aktivitasbelajar Akuntansi dari siklus I ke siklus II. Hasil observasi yang diperoleh dari indikatormembaca materi, mengajukan pertanyaan kepada guru atau teman, mengemukakan pendapatatau gagasan saat diskusi kelompok atau presentasi kelompok, menanggapi pendapat oranglain, memperhatikan atau mendengarkan penjelasan materi dari guru dan teman lain,membuat catatan, melakukan diskusi dalam kelompok, mengerjakan tugas yang telahdiberikan oleh guru, dan kepedulian terhadap kesulitan sesama anggota kelompokmenunjukkan bahwa telah terjadi peningkatan skor rata-rata aktivitas belajar Akuntansi yakni65,32% pada siklus I menjadi 88,55% pada siklus II. Peningkatan aktivitas belajar Akuntansijuga terlihat dari skor rata-rata angket yang menujukkan angka sebesar 75,42% pada siklus I,dan meningkat menjadi 91,75% pada siklus II. Hasil wawancara untuk aktivitas belajarAkuntasi menunjukkan bahwa selama pembelajaran berlangsung, seluruh indikatormenunjukkan skor di atas 75%. Respons siswa terhadap pembelajaran Think Pair Shareadalah positif. Hal ini terbukti dari hasil penelitian yang dipeoleh dari angket denganmenggunakan empat indikator respons yakni ketertarikan, manfaat, kendala, serta harapandan saran untuk model pembelajaran Think Pair Share menunjukkan skor rata-rata 76,43%.Hasil angket ini juga didukung dari hasil wawancara yang diperoleh. Hasil wawancara dariseluruh indikator respons siswa terhadap model pembelajaran kooperatif tipe Think PairShare menunjukkan skor di atas 90%.Kata kunci : aktivitas belajar Akuntansi, respons, TPS, SMA Negeri 2 Wonosari
PENDAPAT ANGGOTA-ANGGOTA DPR-RI MENGENAI INDEPENDENSI AUDITOR NEGARA (BPK)
Authors: Suharyani Suharyani
Published: January 2019

PENDAPAT ANGGOTA-ANGGOTA DPR-RI MENGENAI INDEPENDENSI AUDITOR NEGARA (BPK)This research, which is meant as a contribution to state financial control, focusing on the opinion of Indonesian Legislative Assembly members regarding state auditors independence (State Audit Board) viewed from micro perspective.  Here are two research questions (a)Do legislative members perceive that state auditors have independence attitude; (b)What factors are influencing the opinion of legislative members regarding state auditors independence. The researcher surveyed 70 legislative members from various faction, commission, education level, gender, and age by personally administered questionnaire technique.  Respondents are determined by stratified sampling and convenience sampling method.  Data are measured by Likert (ordinal) scale point 5.  First hypothesis testing analyze whether legislative members perceive that state auditors are independence performed by mean testing method.  While variables which are presumed influencing legislative members opinion are education level, age, gender, and political party (faction) origin (faction).  To test whether these four variables by individual influence respondent opinion significantly, the researcher use one way Anova method. The result shows legislative members perceive that state auditors weren’t independence. Except gender variable, the researcher found significant different opinion between respondents group classified by education level, age group, and political party origin.  In general, respondents group having degree of S3, elder than 60 year, and coming from Reformasi Faction have a more critical opinion compared to other groups.   Keywords : state auditor independence.
ANALISIS PERBANDINGAN KINERJA KEUANGAN PERBANKAN ASEAN (STUDI PADA BANK UMUM INDONESIA, THAILAND DAN FILIPINA)
Authors: Wahyuni Anggun , Sukirno Sukirno
Published: January 2019

Penelitian ini bertujuan untuk mengetahui perbandingan kinerja keuangan industri perbankan Indonesia dengan negara ASEAN lainnya (Thailand dan Filipina) menggunakan indikator RGEC. Penelitian ini termasuk ke dalam penelitian komparatif. Populasi dalam penelitian ini adalah industri perbankan di Indonesia, Thailand dan Filipina. Pemilihan sampel menggunakan metode judment sampling. Seluruh sampel terdiri dari 3 bank di Indonesia, 3 bank di Thailand dan 3 bank di Filipina. Total sampel sebanyak 36 data termasuk didalamnya adalah sampel dengan periode 4 tahun (2011, 2012, 2013 dan 2014). Model statistik yang digunakan untuk menguji hipotesis menggunakan uji parametrik one-way ANOVA. Hasil penelitian menunjukkan bahwa seluruh indikator rasio keuangan perbankan Indonesia adalah signifikan berbeda dengan kinerja keuangan perbankan kedua negara ASEAN, kecuali rasio CAR. Rata-rata rasio keuangan perbankan Indonesia lebih baik dibandingkan dengan rata-rata tiga negara ASEAN lainnya pada rasio NPL, ROA, NIM dan CAR sedangkan rasio LDR menunjukkan lebih baik rata-rata negara ASEAN lainnya. Kata kunci:     Kinerja Keuangan Perbankan, ASEAN, RGEC, NPL, LDR, ROA, NIM, CAR
Источники спонтанного излучения на основе арсенида индия (обзор: десять лет спустя)
Authors: Карандашев С.А. , Матвеев Б.А. , Ременный М.А.
Published: January 2019

AbstractThe results of investigations of light-emitting diodes based on heterostructures with an InAs active region grown by liquid phase and metalorganic vapor-phase epitaxy over the last decade are reviewed. The near-field pattern, L – I and I – V characteristics, and quantum efficiency of point-contact and flip-chip light-emitting diodes are analyzed in a wide temperature range.
Особенности свойств редкоземельных полупроводников
Authors: Каминский В.В. , Шаренкова Н.В.
Published: January 2019

AbstractIt is shown that the unique features of the physical properties of rare-earth semiconductor compounds are based on the small values of the ionization potentials of the rare-earth elements included in them. The reason for this is the presence of 4 f shells in the electronic structure of the elements.
Влияние температуры отжига на электрически активные центры в кремнии, имплантированном ионами германия
Authors: Соболев Н.А. , Александров О.В. , Сахаров В.И. , Серенков И.Т. , Шек Е.И. , Калядин А.Е. , Паршин Е.О. , Мелесов Н.С.
Published: January 2019

AbstractThe implantation of Czochralski-grown p -type silicon with 1-MeV germanium ions at a dose of 2 . 5 × 10^14 cm^–2 does not lead to the amorphization of single-crystal silicon. Under subsequent high-temperature annealing, electrically active acceptor centers are transformed. Their concentration and special distribution depend on the annealing temperature. The possible factors determining how these centers are formed are discussed.
Дислокационная фотолюминесценция в кремнии, имплантированном ионами германия
Authors: Соболев Н.А. , Калядин А.Е. , Сахаров В.И. , Серенков И.Т. , Шек Е.И. , Паршин Е.О. , Мелесов Н.С. , Симакин С.Г.
Published: January 2019

AbstractThe influence exerted by the conditions of the post-implantation annealing of silicon implanted with germanium ions on how luminescence centers are formed is studied. Measurements by the technique of the Rutherford backscattering of medium- and high-energy ions demonstrates that implantation with 1-MeV germanium ions at a dose of 1 . 5 × 10^14 cm^–2 does not lead to the amorphization of single-crystal silicon. It is found that subsequent high-temperature annealing of the implanted samples in a chlorine-containing atmosphere at a temperature of 1100°C for 0.5–1.5 h gives rise to so-called D1 and D2 dislocation-related luminescence lines with wavelengths of 1.54 and 1 . 42 μm. With increasing annealing duration, the intensity of the D1 line decreases and that of D2 remains constant, but the D1 line dominates in all the spectra. The possible factors responsible for a decrease in the intensity of the D1 line and, in particular, the diffusion of germanium atoms and the formation of a silicon–germanium solid solution are discussed.
Лазерный отжиг тонких пленок ITO на гибких органических подложках
Authors: Паршина Л.С. , Новодворский О.А. , Храмова О.Д. , Лотин А.А. , Хоменко М.Д. , Щур П.А.
Published: January 2019

AbstractIndium–tin oxide (ITO) thin films on polyethylene-terephthalate film substrates are fabricated at room temperature by reactive magnetron sputtering. The minimum of the resistivity of ITO films formed at room temperature is 4.5 × 10^–4 Ω cm. The laser annealing of ITO films from 140 to 600 nm in thickness increases their conductivity from 10 to 24% depending on the energy density to the film and irradiation dose. It is established that the laser annealing of films up to 250 nm in thickness is efficient at an energy density in the range from 12 to 35 mJ/cm^2. Films from 390 to 600 nm in thickness should be annealed by laser radiation with an energy density of no lower than 46 mJ/cm^2. A model problem taking into account the influence of radiative cooling and heat exchange of the film and the substrate on the variation in the film temperature over time during laser annealing is considered. A one-dimensional thermal conductivity equation for a bilayer medium is used. The maximal stresses in the ITO film under various annealing modes are calculated.
Структурные, оптические и фоточувствительные свойства пленок PbS, осажденных в присутствии CaCl-=SUB=-2-=/SUB=-
Authors: Маскаева Л.Н. , Мостовщикова Е.В. , Марков В.Ф. , Воронин В.И.
Published: January 2019

AbstractPolycrystalline lead-sulfide (PbS) films doped with calcium are synthesized on sitall and glass substrates by chemical bath deposition with the use of thiocarbamide and a CaCl_2 additive at concentrations of up to 5 mM. Introduction of the CaCl_2 additive into the reaction solution greatly prolongs the induction period of the process of synthesis. The thicknesses of the PbS and PbS(Ca) films are, correspondingly, 200 and 150 nm at an average crystallite dimension of ~100 nm. The maximum calcium content in the films is 0.06 at % for layers on sitall substrates and 0.11 at % for layers on glass substrates. Doping with calcium does not influence the crystal structure of lead sulfide (the cubic B 1 structure, space group Fm 3 $$\bar {m}$$ ) but brings about an increase in the crystal-lattice period from a = 0.59343(2) nm to a = 0.59413(1) nm, an increase in microstrains, and partial ordering of the crystallites forming the film. Upon the introduction of calcium, the band gap decreases from E _ g = 0.40 eV at 295 K (0.38 eV at 90 K) to E _ g = 0.38 eV (0.37 eV). The introduction of up to 5 mM of CaCl_2 into the reaction mixture increases the voltage–power sensitivity of the films by a factor of ~1.7, which is attributed to oxygen-containing compounds formed in the films as a result of the increase in the induction period of the process of synthesis.
Способ создания просветляющих покрытий для пленок ITO
Authors: Марков Л.К. , Павлюченко А.С. , Смирнова И.П.
Published: January 2019

AbstractA technique for forming transparent conducting indium-tin-oxide films for applications, which require high current densities, are considered. These films have to combine a good surface conductivity with an increased transmittance of radiation within a wide wavelength range. A two-stage process is designed to fabricate such coatings: at the first stage, a dense indium-tin-oxide film with high electrical conductivity is formed; then, an additional antireflection layer of the same material is deposited. Possible methods for optimizing these additional indium-tin-oxide films obtained by forming nanostructured self-assembled coatings on the surface of dense films are investigated. It is shown that the best light extraction over a wide wavelength range is provided by the composite film-deposition technique, which consists in the deposition of self-assembled nanostructured coatings by electron-beam evaporation on a hot substrate and the further filling of voids by magnetron sputtering at room temperature. Since the optical properties of the obtained antireflection coatings depend on the mass ratio of materials deposited at each stage, the technique makes it possible to optimize the film properties on the basis of problems specified by the area of their application. Computer simulation of the behavior of the material distribution in the structure of the studied coatings confirms the ability of the method of combined film deposition to form the smoothest character of the change in the effective refractive index of the coating structure, which leads to the most efficient extraction of optical-range light.
Фотоэлектрические свойства слоев GaN, выращенных методом молекулярно-лучевой эпитаксии с плазменной активацией на подложках Si(111) и эпитаксиальных слоях SiC на Si(111)
Authors: Кукушкин С.А. , Мизеров А.М. , Гращенко А.С. , Осипов А.В. , Никитина Е.В. , Тимошнев С.Н. , Буравлев А.Д. , Соболев М.С.
Published: January 2019

AbstractThe photoelectric properties of GaN/SiC/Si(111) and GaN/Si(111) heterostructures grown by plasma-assisted molecular-beam epitaxy under the same growth conditions on identical silicon substrates, but with different buffer layers, are experimentally investigated. The GaN/SiC/Si(111) structure is formed on a Si substrate with the SiC buffer layer grown by a new atom-substitution technique and the GaN/Si(111) structure, on a Si substrate subjected to pre-epitaxial plasma nitridation. The significant effect of carbon-vacancy clusters contained in the SiC layer on the growth of the GaN layer and its optical and photoelectric properties is found. It is experimentally established that the GaN/SiC/Si(111) heterostructure has a higher photosensitivity than the GaN/Si(111) heterostructure. In the GaN/SiC/Si(111) heterostructure, the coexistence of two oppositely directed p – n junctions is observed. One p – n junction forms at the SiC/Si interface and the other, at the GaN/SiC interface. It is shown that the occurrence of an electric barrier in the GaN/Si(111) heterostructure at the GaN/Si(111) heterointerface is caused by the formation of a thin silicon-nitride transition layer during pre-epitaxial plasma nitridation of the Si(111) substrate.
Передача энергии электронного возбуждения в масcиве квантовых точек CdS на квазидвумерной поверхности
Authors: Бондарь Н.В. , Бродин М.С. , Матвеевская Н.А. , Бейник Т.Г.
Published: January 2019

AbstractThe optical spectra of films composed of spherical silicon-dioxide particles coated with small-radius CdS quantum dots are recorded and analyzed. Large shifts of the absorption and photoluminescence bands are detected and studied in relation to the concentration of quantum dots and to the pumping density and wavelength. Analysis of the experimental data shows that the effects are due to electronic excitation energy transfer by particles through the mechanism of tunneling induced by a strong interaction between quantum dots. The results obtained at low pumping densities and different excitation wavelengths make it possible to describe the size distribution of CdS quantum dots. This distribution can be adequately approximated with a Gaussian function.
Плазмонное усиление поля в фотоприемниках среднего ИК-диапазона на базе квантовых точек Ge/Si с различной толщиной активной зоны
Authors: Блошкин А.А. , Якимов А.И. , Двуреченский А.В.
Published: January 2019

AbstractThe spatial distribution of the electric field in Ge/Si photodetector heterostructures coated with a gold film containing a regular two-dimensional array of subwavelength apertures is calculated by the finite-element method. The array period and aperture diameter are 1.2 and 0.7 μm, respectively. The efficiency of field enhancement is determined for different thicknesses of the active region occupied by quantum dots. It is demonstrated that the field-enhancement factor for an electromagnetic wave incident on the structure from the side of the substrate is ~3.5 times larger than that for a wave incident from the opposite side. In the first case, the field-enhancement factor varies nonmonotonically with the thickness of the active region.
Дискриминация поперечных мод в торцевых полупроводниковых лазерах с пространственной модуляцией отражения выходных зеркал
Authors: Гордеев Н.Ю. , Паюсов А.С. , Мухин И.С. , Серин А.А. , Кулагина М.М. , Гусева Ю.А. , Шерняков Ю.М. , Задиранов Ю.М. , Максимов М.В.
Published: January 2019

AbstractA post-growth technique aimed at spatial modification of facet reflectance of edge-emitting diode lasers has been proposed. It is based on the deposition of an anti-reflection coating and subsequent precise etching with a focused ion beam. The technique allowed suppressing of high-order lateral modes in 10 μm stripe lasers based on ten layers of InAs/InGaAs quantum dots.
Микромассивы кремниевых нанопилларов: формирование и резонансное отражение света
Authors: Басалаева Л.С. , Настаушев Ю.В. , Дульцев Ф.Н. , Крыжановская Н.В. , Моисеев Э.И.
Published: January 2019

Abstract —The results of investigating the spectral characteristics of reflection from silicon nanopillar (Si NP) microarrays in the wavelength region from 400 to 1100 nm are presented. The Si nanopillars are formed by electron lithography on a negative resist with subsequent reactive ion etching. The Si nanopillars are etched through a resist mask and SiO_2 100 nm thick. In the spectra of reflection from nanopillar microarrays, minima are observed, the position of which depends strongly on the Si nanopillar diameter.
Влияние электрического поля на энергию активации локальных уровней в полупроводниках со слоистой (GaSe) и кубической структурой (Ga-=SUB=-2-=/SUB=-Se-=SUB=-3-=/SUB=-)
Authors: Пашаев А.М. , Тагиев Б.Г. , Тагиев О.Б. , Межидова В.Т. , Садыхов И.З.
Published: January 2019

AbstractThe results of measuring the electrical conductivity of layered crystals (GaSe, GaTe, and their solid solutions) and cubic crystals (Ga_2Se_3) in strong electric fields (up to 5 × 10^5 V/cm) in the temperature range of 77–300 K are presented. These results are compared with predictions of the phenomenological theory of concentration instability in semiconductors. This theory considers the role of the Frenkel effect, which is related to the thermionic ionization of traps causing instability in semiconductors with an S -shaped current–voltage ( I – V ) characteristic. Based on the results of measuring the electrical conductivity of layered and cubic crystals exhibiting the Frenkel effect and described by the theory of current instability in semiconductors, the free-carrier concentration in the aforementioned types of chalcogenide semiconductors is estimated to be n  = (3 × 10^13–4 × 10^15) cm^–3.
Влияние замещения висмута празеодимом и лантаном на термоэлектрические свойства оксиселенидов BiCuSeO
Authors: Новицкий А.П. , Сергиенко И.А. , Новиков С.В. , Кусков К.В. , Лейбо Д.В. , Панкратова Д.С. , Бурков А.Т. , Ховайло В.В.
Published: January 2019

AbstractThe  results  of  investigating  the  thermoelectric  properties of the bulk р -type oxyselenides Bi_1 –_ x Pr_ x CuSeO ( x = 0, 0.04, 0.08) and Bi_0.96La_0.04CuSeO obtained by the solid-state reaction technique are presented. The temperature dependences of the thermopower, electrical resistivity, and thermal conductivity are measured at temperatures from room temperature to 800 K. Over the whole temperature range, a decrease in the electrical resistivity and thermopower is observed with increasing substitution level, while the thermal conductivity is almost unaffected by the substitution of rare-earth elements for bismuth. Despite the nominal valence of Bi, La, and Pr being the same, the replacement of bismuth by rare-earth ions leads to an increase in the charge-carrier concentration, which may be caused by a difference in the electronic configurations of ions, resulting in a shift of the Fermi level to the valence band.
Терморезистивный полупроводниковый SiC/Si-композиционный материал
Authors: Брантов С.К. , Якимов Е.Б.
Published: January 2019

AbstractA new method for growing a layer of self-bonded silicon-carbide crystallites on the surface of a flexible carbon foil with subsequent impregnation of the formed structures by silicon melt is developed. Thermistors for a temperature range of 900–1450 K with s thermal sensitivity attaining 11 350 K able to be used in air are fabricated based on this composite material. The structural and electrophysical characteristics of the mentioned material are investigated.
Оптические свойства полиэтилена, наполненного нанокристаллитами Bi-=SUB=-2-=/SUB=-Te-=SUB=-3-=/SUB=-
Authors: Гамзаева А.Ю. , Ализаде Э.Г. , Мамедов Н.Т. , Абдуллаев Н.А. , Амирасланов И.Р. , Алиева Е.Н. , Ахмедова Х.Н. , Аждаров Г.Х. , Кахраманов К.Ш. , Немов С.А.
Published: January 2019

AbstractComposite mixtures with various component concentrations are fabricated by the thermal pressing of low-density polyethylene and Bi_2Te_3 in the powder-like state with a nanocrystal size of ~50 nm. These samples preliminarily characterized by X-ray diffractometry and Raman spectroscopy are investigated by spectroscopic ellipsometry in a photon energy range of 1–6 eV. The dielectric functions for composites with a nominal Bi_2Te_3 weight concentration of 5, 10, 30, 40, 50, 60, and 70% are calculated based on the measured optical constants of polyethylene and the Bi_2Te_3 crystal in the approximation of the Bruggeman effective medium. The analysis of depolarization features of reflected light makes it possible to establish the actual inhomogeneity of the composite samples under study caused by the clusterization of nanocrystallites with an increase in the Bi_2Te_3 weight concentration in polyethylene and propose the most reliable optical model of the formed composites.
Особенности МДП-структур с фторидом самария на кремниевых и германиевых подложках
Authors: Шалимова М.Б. , Сачук Н.В.
Published: January 2019

AbstractThe electrophysical characteristics of silicon and germanium MIS structures with an SmF_3 insulator film, as well as their degradation due to the effect of electric fields, although similar, have a number of specific features. The current-transmission mechanism in all studied structures is described by the power dependence. Interface traps form the charge of electrically active traps, which varies during capacitance–voltage measurements, and the charge of inactive traps, which remains invariable. This charge is negative on the n -Ge surface, and the corresponding charge on the n -type and p -type silicon surface is positive. The trap charge density in the bulk of samarium fluoride lies in the range from –0.2 × 10^–8 to 0.6 × 10^–8 C/cm^2 and is negligibly small when compared with the charge of interface traps in most cases.
Влияние концентрации водорода на фототок диодов Шоттки Pd/n-InP
Authors: Гребенщикова Е.А. , Сидоров В.Г. , Шутаев В.А. , Яковлев Ю.П.
Published: January 2019

AbstractThe variation rate of the short-circuit photocurrent of Pd/ n -InP Schottky diodes is studied as a function of the presence of hydrogen in a gas mixture with H_2 concentrations of 1–100 vol %. It is shown that upon the simultaneous exposure of the Schottky diode to a hydrogen-containing gas mixture and to light (λ = 0.9 μm), the hydrogen concentration in the gas mixture and the Pd/ n -InP diode photocurrent variation rate are related exponentially. The Schottky-diode response rate to the presence of hydrogen in the gas mixture increases with the illumination intensity.
Низкотемпературные омические контакты на основе Ta/Al к гетероэпитаксиальным структурам AlGaN/GaN на кремниевых подложках
Authors: Ерофеев Е.В. , Федин И.В. , Федина В.В. , Фазлеев А.П.
Published: January 2019

AbstractThe formation features of a low-temperature Ta/Al-based ohmic contact to Al_0.25Ga_0.75N/GaN heteroepitaxial structures on silicon substrates are studied. The fabricated ohmic contacts based on Ta/Al/Ti (10/300/20 nm) compositions have a low contact resistance (0.4 Ω mm) and smooth surface morphology of the contact area and its edge after 60-s annealing at T = 550°C in a nitrogen atmosphere.
Анодное окисление слоев кремний-на-изоляторе, созданных методом водородного переноса
Authors: Тысченко И.Е. , Попов И.В. , Спесивцев Е.В.
Published: January 2019

AbstractThe anodic oxidation rate of silicon-on-insulator films fabricated by hydrogen transfer is studied as a function of the temperature of subsequent annealing. It is established that the oxidation rate of transferred silicon-on-insulator films is five times lower compared to the oxidation rate of bulk single-crystal silicon samples. The oxidation rate increases, as the annealing temperature is elevated in the range 700–1100°C and as the depth of gradually removed anode-oxidized layers is increased. The results obtained in the study are attributed to an increase in the efficiencies of the anodic current and oxygen–silicon interatomic interaction due to the annealing of defects and due to release of hydrogen from the bound state, respectively. The formation of hydrogen bubbles in the surface region of silicon due to the diffusion of hydrogen, released in the process of the oxidation reaction, towards micropores in the silicon-on-insulator layer is detected.
Электрофизические и фотолюминесцентные исследования сверхрешeток \LT-GaAs/GaAs : Si\, выращенных методом молекулярно-лучевой эпитаксии на подложках GaAs с ориентацией (100) и (111)А
Authors: Галиев Г.Б. , Климов Е.А. , Клочков А.Н. , Копылов В.Б. , Пушкарев C.C.
Published: January 2019

AbstractThe results of studying semiconductor structures proposed for the first time and grown, which combine the properties of LT-GaAs with p -type conductivity upon doping with Si, are presented. The structures are {LT-GaAs/GaAs:Si} superlattices, in which the LT-GaAs layers are grown at a low temperature (in the range 280–350°C) and the GaAs:Si layers at a higher temperature (470°C). The p -type conductivity upon doping with Si is provided by the use of GaAs(111)A substrates and the choice of the growth temperature and the ratio between As_4 and Ga fluxes. The hole concentration steadily decreases, as the growth temperature of LT-GaAs layers is lowered from 350 to 280°C, which is attributed to an increase in the roughness of interfaces between layers and to the formation of regions depleted of charge carriers at the interfaces between the GaAs:Si and LT-GaAS layers. The evolution of the photoluminescence spectra at 77 K under variations in the growth temperature of LT-GaAs is interpreted as a result of changes in the concentration of Ga_As and V _Ga point defects and Si_Ga– V _Ga, V _As–Si_As, and Si_As–Si_Ga complexes.
Влияние температуры фотонного отжига на структурные и оптические свойства пленок ZnO, синтезированных методом дуального магнетронного распыления
Authors: Зайцев С.В. , Ващилин В.С. , Колесник В.В. , Лимаренко М.В. , Прохоренков Д.С. , Евтушенко Е.И.
Published: January 2019

AbstractZinc-oxide films 1.4 μm in thickness are deposited onto glassy substrates by the dual magnetron-assisted sputtering of zinc targets in an argon and oxygen gas atmosphere. The dependences of the structural and optical characteristics of the ZnO films on the temperature of postdeposition photonic annealing are studied. It is established that an increase in the annealing temperature yields an increase in the degree of crystallinity of the films. Electron microscopy shows that the deposited ZnO coatings are columnar in structure and the microstructure density and crystallite size increase upon annealing. It is found that, at an annealing temperature of 450–650°C, the optical transmittance increases to >90% in the spectral range 400–1100 nm. The experimental results show that the temperature of vacuum photonic annealing has the most profound effect on the final properties of ZnO coatings.
Исследование возможности изготовления напряженных сверхрешеток InAs/GaSb методом газофазной эпитаксии из металлоорганических соединений
Authors: Левин Р.В. , Неведомский В.Н. , Баженов Н.Л. , Зегря Г.Г. , Пушный Б.В. , Мизеров М.Н.
Published: January 2019

AbstractThe first results showing the possibility of manufacturing InAs/GaSb superlattices by the metal-organic chemical vapor deposition (MOCVD) method are presented. The possibility of manufacturing heterostructures with an InAs/GaSb strained superlattice with layer thicknesses of 2–4 nm is experimentally demonstrated. The 77-K electroluminescence spectra of the structures show a long-wavelength peak at around 5 . 0 μm (0 . 25 eV). This peak is probably associated with the strained superlattice because solid solutions that could form on the basis of composite compounds do not provide this carrier-recombination energy.
Очистка от оксидов поверхности пластин полупроводника InSb для создания латеральных спиновых клапанов
Authors: Виглин Н.А. , Грибов И.В. , Цвелиховская В.М. , Патраков Е.И.
Published: January 2019

AbstractsThe formation conditions of a smooth and oxide-free surface of InSb semiconductor with the purpose of fabricating lateral spin devices based on it are investigated. The dry etching rate by Ar ions of the surface of the crystalline faces (100) of InSb plates as well as a variation in their roughness depending on the power supplied to ion etching devices are investigated. The degree of oxidation of the semiconductor surface exposed to air after ion cleaning and annealing in molecular hydrogen are evaluated. Based on comparison of the efficiency of spin injection in devices formed with semiconductors subjected to various types of treatment, a conclusion is made about the parameters of optimal preparation of the surface of the InSb wafers for the fabrication of lateral spin devices.
Техника электрохимического вольт-фарадного профилирования сильно легированных структур с резким профилем распределения примеси
Authors: Фролов Д.С. , Яковлев Г.Е. , Зубков В.И.
Published: January 2019

AbstractThe specific features of applying electrochemical capacitance–voltage profiling to investigate heavily doped structures with a sharp doping profile are considered. Criteria are presented, and recommendations are given for selection of the optimal measurement parameters, and the necessity of increasing the frequency, at which the capacitance is measured during profiling, is substantiated. The described procedure is considered by the example of profiling p -type silicon structures with ion implantation as well as n -GaAs epitaxial and substrate structures for p HEMT devices.