bluuebunny/crossref_metadata_2025 huggingface dataset:
Rīgas Politehnikuma un Rīgas Politehniskā institūta (1862–1919) studenti – literāti
Authors: Zigmunde Alīda , Lanka Ērika , Stikute Elita , Šlegelmilha Zanda
Published: May 2019

Rakstā apkopots Rīgas Politehnikuma (RP) un Rīgas Politehniskā institūta (RPI) kādreizējo studentu – dramaturgu, dzejnieku un rakstnieku – veikums literatūrā, kā arī raksturota viņu darbība. Augstskolā studējuši vairāki latviešu un cittautu literāti. Inženiera diplomu, studējot Inženieru, Komercijas un Lauksaimniecības nodaļās, ieguvuši vien seši no viņiem – Alfrēds Andersons, Jānis Bergs, Rihards Ērglis, Ernests Eferts, Jānis Miķelsons un Arvīds Valdmanis. Augstskolā studējuši arī latviešu rakstnieks Jānis Poruks un krievu rakstnieks Mihails Prišvins, kuri, tāpat kā daži citi, par  inženieriem nekļuva, bet ir pazīstami, pateicoties veikumam daiļliteratūrā. Dzejoļus rakstījis arī absolvents admirālis Teodors Spāde. Raksts tapis, izmantojot RTU Inženierzinātņu vēstures pētniecības centra (IVPC) krājumu, arhīvu un bibliotēku materiālus. Tajā pirmo reizi apkopotas ziņas par RP / RPI studentiem – literātiem un sniegts īss viņu raksturojums.
Rīgas Politehniskā institūta studenta, psalmotāja Jāna Jurjena dzīves un darba gaitas (1866–1915)
Authors: Coja Sergejs
Published: May 2019

Pareizticīgais igaunis Jāns Jurjens 1888. gadā absolvēja Rīgas Pareizticīgo Garīgo semināru, 1902. gadā – Sanktpēterburgas Garīgo akadē- miju. No 1907. līdz 1910. gadam viņš studēja Rīgas Politehniskā institūta (RPI) Lauksaimniecības nodaļā. 19. gadsimta beigās un 20. gadsimta sākumā J. Jurjens kalpoja pareizticīgajai baznīcai un ticīgajiem kā psalmotājs, tautskolu skolotājs  un Rīgas Pareizticīgo Garīgā semināra pedagogs. Viņš ir vairāku grāmatu un zi- nātnisko rakstu autors.
In Memoriam
Authors: Zigmunde Alīda , Jure Māra , Turks Māris , Krastiņš Jānis , Ērglis Artis , Pozemkovska Maija
Published: May 2019

2017. gada 29. decembrī mūžībā aizgāja Latvijas  Zinātņu  akadē­ mijas (LZA) korespondētājloceklis, RTU Goda darbinieks (2015), Datorzinātnes  un   informācijas    tehnoloģijas    fakultātes    (RTU DITF)   Programmatūras   inženierijas   katedras   vadītājs   profesors  Dr. habil. sc. ing. Leonīds Novickis.2017. gada 14. septembrī mūžībā aizgāja RTU profesors, Latvijas Zinātņu akadēmijas (LZA) akadēmiķis, RTU Goda darbinieks (2012) Kārlis Rocēns.Vasaras vidū, 5. jūlijā, mūžības ceļos devās RTU Goda darbinieks (2006), Mašīnzinību, transporta un aeronautikas fakultātes Mašīnbūves tehnoloģijas institūta direktors, Aparātu būvniecības katedras vadītājs, profesors un vadošais pētnieks Dr. habil. sc. ing. Jānis Rudzītis.1.februārī pārtrūka inženiera ķīmiķa Dr. habil. chem. Augusta Rupļa mūžs.2017. gada 4. decembrī 76 gadu vecumā mūžības ceļos devās Kaspars Andris Rutks, laikabiedriem pazīstams kā Kaspars Rutks. 2017. gada 17. septembrī mūžībā aizgāja Latvijas Zinātņu akadēmijas (LZA) akadēmiķis, RTU Goda darbinieks (2004), RTU emeritētais profesors Dr. habil. chem. Andris Strakovs.2017. gada 21. septembra rīts atnesa skumju vēsti Latvijas arhitektu saimei un ikvienam ar Latvijas kultūrvides tēla attīstību un problemā­ tiku saistītam cilvēkam: viņsaules ceļos devies ilggadējais RTU Arhi­ tektūras fakultātes profesors, RTU Goda darbinieks (2012), habilitētais arhitektūras zinātņu doktors un Latvijas Zinātņu akadēmijas (LZA) Goda doktors Ivars Strautmanis.2017. gada 18. novembrī mūžības ceļos devās RTU Elektronikas un telekomunikāciju fakultātes dekāna vietnieks mācību darbā docents Andrejs Strauts.2018. gada 25. aprīlī mūžības ceļos devās izcilais latviešu medicīnas vēsturnieks, ilggadējs Paula Stradiņa Medicīnas vēstures muzeja dar­ binieks, Latvijas Zinātņu akadēmijas (LZA) īstenais loceklis profesors Dr. med. h. c. Arnis Vīksna.
Micro-photoluminescence mapping of surface plasmon-coupled emission from InGaN/GaN quantum wells
Authors: Okamoto Koichi , Tateishi Kazutaka , Tamada Kaoru , Funato Mitsuru , Kawakami Yoichi
Published: May 2019

Micro-photoluminescence (PL) mapping was investigated to elucidate the detailed mechanism of surface plasmon (SP)-enhanced emissions from InGaN/GaN quantum wells (QWs) with Ag or Al coating. The PL wavelengths were obviously red-shifted with Ag films, while the PL peak wavelengths were not changed with Al coating. The relationship between the PL peak intensity and the PL wavelength at each pixel showed a positive or negative correlation for the uncoated part of the InGaN/GaN QWs with blue or green emission, respectively. We found that these correlations disappeared in the Ag-coated regions. These results suggest that the energy transfer from the excitons to the SPs should be much faster than that in the exciton localization and charge screening processes of the piezoelectric field in QWs. These effects were not observed for the Al-coated regions because the mechanism of PL enhancement should be quite different as we have suggested previously.
Influence of trap level on an Al0.6Ga0.4N/Al0.5Ga0.5N metal—semiconductor—metal UV photodetector
Authors: Yoshikawa Akira , Ushida Saki , Iwaya Motoaki , Takeuchi Tetsuya , Kamiyama Satoshi , Akasaki Isamu
Published: May 2019

The irradiation intensity and temperature characteristics of each response speed sample are measured to clarify the high photosensitivity mechanism in an Al0.6Ga0.4N/Al0.5Ga0.5N metal–semiconductor–metal photodetector. A tradeoff relation could be observed between the photosensitivity and response speed when the dependence of the saturated photocurrent on the irradiation intensity was investigated by changing the irradiation intensity from 1 nW cm−2 to 45 μW cm−2. The rise time of the photocurrent after exposure to ultraviolet light was measured to determine the trap level density that was estimated to be ca. 1012 cm−2. Further, the decay time constant was obtained by investigating the dependence of the photocurrent decay time on temperature (25 °C–180 °C). By analyzing the Arrhenius plot of the decay time constant versus inverse temperature, trap level depths of 0.23 and 0.67 eV were obtained. Thus, the high photosensitivity in the Al0.6Ga0.4N/Al0.5Ga0.5N photodetector can be attributed to the carriers trapped in deep-level traps.
InGaN quantum wells with improved photoluminescence properties through strain-controlled modification of the InGaN underlayer
Authors: Kusanagi Susumu , Kanitani Yuya , Kudo Yoshihiro , Tasai Kunihiko , Yamaguchi Atsushi A. , Tomiya Shigetaka
Published: May 2019

The effect of internal strain on the luminescence properties of an InGaN single quantum well (SQW) was investigated as a function of modification via an underlayer (UL). Single In0.25Ga0.75N QWs (λ = 520 nm) 3 nm thick were grown on various ULs on a sapphire substrate, where the two UL types included (1) a buffer layer onto which an InGaN layer with a very small amount of In was inserted and (2) a buffer layer grown using different carrier gases. The SQWs were then analyzed by temperature-dependent time-resolved photoluminescence, scanning electron microscopy and cathodoluminescence. The experimental results show that the density of non-radiative recombination centers and the level of potential fluctuation in the SQWs decrease with insertion of an In
x
Ga1−x
N UL possessing a quite low but sufficient indium content (x = 0.007). The density of non-radiative recombination centers in the SQW on the H2 carrier-grown UL, however, is large.
Realization of GaN PolarMOS using selective-area regrowth by MBE and its breakdown mechanisms
Authors: Li Wenshen , Nomoto Kazuki , Sundar Aditya , Lee Kevin , Zhu Mingda , Hu Zongyang , Beam Edward , Xie Jinqiao , Pilla Manyam , Gao Xiang , Rouvimov Sergei , Jena Debdeep , Xing Huili Grace
Published: May 2019

GaN PolarMOS is a vertical power transistor incorporating the unique polarization-induced bulk doping scheme in III-nitrides for the body p-n junction. We report the realization of this device, wherein the vertical channel, source contact, and body contact regions are successfully formed using three steps of selective-area epitaxial regrowth, all by molecular beam epitaxy (MBE). The fabricated PolarMOS has an excellent on-current of >500 mA mm−1 and a specific on-resistance of 0.66 mΩ · cm2. The reverse breakdown mechanisms of the PolarMOS are investigated. First, a pronounced source-drain vertical leakage is identified and attributed to the passivation of the buried p-type body, which is subsequently resolved by the sidewall activation method. With the body leakage eliminated, the breakdown voltage is found to be limited by a highly conductive path along the regrowth sidewall interface using the conductive scanning probe technique, despite the absence of apparent structural defects.
Correlation between nanopipes formed from screw dislocations during homoepitaxial growth by metal-organic vapor-phase epitaxy and reverse leakage current in vertical p–n diodes on a free-standing GaN substrates
Authors: Usami Shigeyoshi , Tanaka Atsushi , Fukushima Hayata , Ando Yuto , Deki Manato , Nitta Shugo , Honda Yoshio , Amano Hiroshi
Published: May 2019

We fabricated p−n diodes under different growth pressures on free-standing GaN substrates of the same quality and observed a noteworthy difference in the reverse leakage current. A large reverse leakage current was generated by nanopipes, which were formed from screw dislocations in the homoepitaxial layer. There were two types of screw dislocation observed in this study. The first type already existed in the substrate and the other was newly generated in the epilayer by the coalescence of edge and mixed dislocations. An increase in the growth pressure suppressed the transformation of screw dislocations into nanopipes, which led to a reduction in the reverse leakage current. To reduce the leakage current further, it is necessary to apply growth conditions that do not transform screw dislocation into nanopipes and to use a free-standing substrate without threading dislocations, that become nanopipes.
Exploration on the Effectiveness of Radio Frequency Treatment and Flash Pasteurisation on Enzyme and Microbial Activity for Coconut Water Preservation
Authors: Eswaran Gnana Moorthy , . Vidyalakshmi , Anand Tito , Hema Vincent
Published: May 2019

The aim of this research work is to explore the effect of flash pasteurisation (FP) and radio frequency (RF) treatment on enzyme activity, microbial activity and physicochemical properties of matured coconut water (MCW). The process conditions for FP were treatment temperature and time in combinations. The process conditions for RF treatment were different electrode position with constant current load 0.8 A. The results obtained from these treatments reveal that FP conditions had significant effect on inactivation of natural microbial flora, polyphenoloxidase (PPO) and peroxidase (POD) activity. From the results it is observed that FP at 90°C for 10 minutes is better for complete enzyme and microbial inactivation than RF treated MCW. The result is also evident that PPO has higher thermal stability than POD. From observed results the study also concludes that, FP is a better option for enzyme and microbial inactivation but RF treatment was found superior for retaining physicochemical attributes.
Incidence and Outcomes of Community Acquired Pneumonia in Patients with Chronic Obstructive Pulmonary Disease at King Abdulaziz Medical City, Riyadh
Authors: Mohan Sreekanth , Almutairi Maryam , Alnaimi Roaa , Alshehri Taif , Philip Winnie , Ismaiel Yassin , Ismaeil Taha
Published: May 2019

Aims: The aim of the study was to estimate the incidence of Community-acquired pneumonia (CAP) among patients with chronic obstructive pulmonary disease (COPD).

Study Design:  A retrospective cohort study.

Place and Duration of Study: King Abdulaziz Medical City in Riyadh between January 2016 to March 2018.

Methodology: From the medical file, we identified patients with COPD diagnosis who admitted to the hospital. Then we identified the patient who develop CAP after the diagnosis date of the COPD. Other variables such as demographic factors, clinical outcome, comorbidity disease, length of stay in the hospital, and mortality were identified for each patient using their electronic medical file.

Results: Out of 363 COPD patients, 122 (33%) had developed CAP after the date of COPD diagnosis.  Based on patient characteristics, the mean age of them was 75.39 years SD was 9.76 and 65% of the patients were female. The available evidence indicates that the mortality rate was n=22 (18.0%). Among those patient, 33 patients were admitted to ICU (27.0%) the rest of patients either wards n= 59 (48.4%) or both n=28 (23.0%). Among our study population, 97.4% had hypertension, 88.6% of the patients had diabetes, and 28.9% had renal failure.  Majority of the study population have been placed on non-invasive ventilation n=94 (77.0%).

Conclusion: This study has been shown that COPD patients had increased risk of CAP. Patients who have multiple comorbidity diseases and got CAP with COPD have a higher risk of morbidities and mortality rate, especially elderly patients.Mention the design of the study here.
Psychometric Properties of Iranian Elder Abuse Questionnaire (Long Form)
Authors: Ghahari Shahrbanoo , Yeke Fallah Maryam , Talemi Abouzar Nouri , Zarghami Mehran , Viesy Fatemeh , Khademolreza Nooshin , Ghayoomi Raoofeh,
Published: May 2019

Aim: Increasing elder population has ledto Elder abuse as an extensively recognized complicated general health issues. This study was carried out to examine psychometric properties of Iranian Elder Abuse Questionnaire.

Methodology: This study was performed within two steps using combined qualitative-quantitative method. At first step, authors interviewed psychologists and elderly people using phenomenology method to determine the concept of elder abuse. Then the questionnaire was developed to address elder abuse. At second step, validity of instrument and internal consistency of questionnaire were examined. Statistical population consisted of all elder persons living in Alborz Province in Iran; of them, 400 members were selected as sample members using convenient sampling method. Results: According to the results obtained from first step, questionnaire consists of 43 items. The results of explanatory factor analysis indicate 13 factors including emotionalabuse, neglect, ignoring needs, compulsion, financial abuse, insulting, deprivation, imposition, secrecy, domination, psychological pressure, mistreatment, and sexual humiliation; these 13 factors could explain 71.06% of variance of thequestionnaire. The obtained Cronbach’s alpha coefficient (0.86) indicates suitable internal consistency of questionnaire.

Conclusion: Considering the psychometric properties this questionnaire the Ghahar’s Elder Abuse Questionnaire is a suitable instrument to evaluate different dimensions of elder abuse in Iranian community.
Scientific and Technical Experiment for Manufacturing Silage in Jordan
Authors: Alnhood Adnan , Massimi Mohunnad
Published: May 2019

Silage is a feed material that has been widely used in previous periods because it has an effective and useful role in feeding animals, saving in the cost of feed and increasing productivity. From the scientific-practical view it is considered as a feed material preserved in an anaerobic environment that ferments sugars and carbohydrates and thus produces organic acids (lactic, citric, and butyric acids), where organic acids work to keep feed material for long periods. A lot of practical experiments have been done to reach the best high-protein percentage mixture. This extension project was designed and implemented in 2017 by the Jordanian Ministry of Agriculture in collaboration with farmers and scientific research stations of the National Center for Agricultural Research. Ten feed mixtures were prepared with the necessary laboratory tests to determine the quality of the produced silage. Mixings of the fodders of alfalfa and corn were made with varying percentages of the two components so that the total does not exceed 100%. In addition, 5 mixtures were made of the first five mixtures, with a total of only 200%. After laboratory testing, the highest protein percentage was found to be 15.25% when fodders of corn mixed 100% with alfalfa by 100%. It is recommended to make this mixture for livestock breeders, especially cow breeders without adding molasses and industrial additives so that the highest yield is achieved, saving in the cost of feed and increasing productivity. This short scientific article aims at presenting a technical and scientific experiment for the production of the best silage by the highest protein level through the use of various mixtures of corn and alfalfa.
ANALISA KESADARAN BIOPHILIA PADA MAHASISWA CALON PENGGUNA GEDUNG P1 DAN P2 UNIVERSITAS KRISTEN PETRA SURABAYA
Authors: Subroto Mitha Angreani , Priatman Jimmy , Rahardjo Jani
Published: May 2019

Biophilia adalah ilmu yang mempelajari keinginan manusia untuk berafiliasi dengan bentuk alam dalam kehidupan. Desain biophilik adalah pengembangan biophilia dalam bidang desain ramah lingkungan, menyediakan kesempatan bagi manusia untuk memiliki hubungan dengan alam. Banyak penelitian yang menunjukkan keuntungan dari desain biophilik, salah satunya adanya peningkatan prestasi mahasiswa pada sekolah dengan penerangan alami.

 

Universitas Kristen Petra Surabaya membangun gedung untuk mahasiswa DKV, interior, sastra, dan ilmu komunikasi, dimana mengutamakan konsep ramah lingkungan. Penelitian ini ditujukan untuk mencari analisa kecenderungan biophilia mahasiswa dikaitkan dengan kesadaran terhadap desain biophilik. Penelitian dilakukan dengan menyebarkan kuesioner pada mahasiswa, mencari korelasi antara kesadaran biophilia dengan desain biophilik.

 

Hasil penelitian menunjukkan tidak ada perbedaan kesadaran biophilia bagi mahasiswa DKV, interior, sastra, dan ilmu komunikasi, maupun berdasarkan angkatan, suku, maupun pengeluaran tiap bulan. Tidak diperlukan adanya perbedaan desain secara spesifik pada jurusan masing-masing. Namun, terdapat beberapa aspek desain yang harus ditingkatkan untuk menciptakan kesadaran biophilia yang lebih tinggi.
MODEL SUMBER DAN PENYEBAB REWORK PADA TAHAPAN PROYEK KONSTRUKSI
Authors: Chundawan Erick , Alifen Ratna Setyawardani
Published: May 2019

Dalam dunia konstruksi, rework merupakan hal yang tidak dapat dihindari. Rework dapat terjadi akibat adanya kesalahan pengerjaan yang disebabkan oleh change, error ataupun omission. Beberapa penelitian menyatakan bahwa penambahan biaya yang diakibatkan karena terjadinya rework pada proyek konstruksi di Surabaya adalah sebesar 5.7% dari total biaya proyek.

 

Pada penelitian ini dilakukan penyebaran kuisioner kepada kontraktor di Surabaya. Kuisioner disusun berdasarkan pada tahapan konstruksi, sumber rework dan penyebab rework guna merancang sebuah model rework pada proyek konstruksi. Dengan dibuatnya model sumber dan penyebab rework para manajer proyek dapat mengantisipasi terjadinya rework sesuai dengan tahapan konstruksi.

 

Hasil penelitian menunjukkan bahwa pada proyek konstruksi, rework sering terjadi pada tahapan finishing. Sumber rework yang harus diperhatikan untuk tahapan pekerjaan finishing adalah adanya perubahan (change) dan diikuti dengan adanya kesalahan yang terjadi (error), akibat faktor kepemimpinan dan komunikasi. Salah satu indikator utama dari penyebab rework yang memiliki intensitas tertinggi adalah kurangnya pengawasan di lapangan dan rencana kerja.

 

In construction, rework is unavoidable. Rework usually occurs due to mistake from workmanship cause by change, error and omission. Additional cost accruing from of rework on a construction project in Surabaya is around 5.7% from the total cost of project.

 

In this research, questionnaires were distributed to contractors in Surabaya. Questionnaires were composed based on the construction phases, the sources and the causes of rework in order to design a model of rework on construction project. With the establishment of the sources and causes model of rework project managers can anticipate the occurrence of rework in accordance with the project construction phase.

 

The research findings show that construction project in general, rework happens frequently in the phase of finishing activity in the construction phase, the sources of rework that must be considered for finishing activity is due to change order and followed by error that is caused by lack of leadership and communication. The highest intensity of the main indicators of the causes is inadequatecy of supervision and job planning.
Roll‐to‐Roll Hot Embossing of 1D and 2D Photonic Nanostructures
Authors: Habermehl Anne , Brenner Philipp , Huber Robert , Mertens Adrian , Winkler Frank , Hahn Lothar , Guttmann Markus , Eschenbaum Carsten , Lemmer Uli
Published: May 2019

Roll‐to‐roll hot embossing is exploited for the fabrication of 1D nanogratings and 2D nanopillar arrays. Critical structure diameters as low as 150 nm and distances down to 50 nm are replicated in a polystyrene foil using flexible nickel shims, which are made using electron beam lithography and subsequent electroplating. The high quality of the as‐fabricated structures is proven by their application in two key nanophotonic components. After evaporation of 250 nm of Alq3:DCM on 1D nanogratings using grating periods between 375 and 415 nm, we can realize tunable organic DFB lasers emitting between 604 and 665 nm. 2D nanopillar arrays are covered with a thermally evaporated Au layer and integrated in microfluidic chips for surface‐enhanced Raman measurements. High and homogeneous enhancement of the Raman signal is achieved using rhodamine 6G as exemplary analyte. For polystyrene nanopillar arrays with pillar diameters of 190 nm, a spacing of 50 nm, and a height of 100 mm coated with a 70 nm thick Au layer, an analytical enhancement factor of ≈4.3 × 104 is demonstrated. The presented work shows the versatility of roll‐to‐roll hot embossing for the low‐cost and large‐area fabrication of nanostructures.
Achieving a High Fill Factor and Stability in Perylene Diimide–Based Polymer Solar Cells Using the Molecular Lock Effect between 4,4′‐Bipyridine and a Tri(8‐hydroxyquinoline)aluminum(III) Core
Authors: Zhang Guangjun , Xu Xiaopeng , Lee Young Woong , Woo Han Young , Li Ying , Peng Qiang
Published: May 2019

Two novel perylene diimide (PDI)–based derivatives, Alq3‐PDI and Alq3‐PDI2, are synthesized by flanking a 3D tri(8‐hydroxyquinoline)aluminum(III) (Alq3) core with PDI and a helical PDI dimer (PDI2) to construct high‐performance small molecular nonfullerene acceptors (SMAs). The 3D Alq3 core significantly suppresses the molecular aggregation of the resulting SMAs, leading to a well‐mixed blend with a PTTEA donor polymer and weak phase separation. Compared with Alq3‐PDI, the extended π‐conjugation of Alq3‐PDI2 results in higher‐order molecular packing, which improves the absorption and phase separation behavior. Thus, the Alq3‐PDI2 devices have higher Jsc and FF values and better device performance, which are further enhanced by a small amount of 4,4′‐bipyridine (Bipy) as an additive. The coordination between Bipy and the Alq3 core promotes molecular packing and phase separation, which lower charge recombination and enhanced charge collection in the resulting devices. Therefore, a largely improved Jsc of 15.74 mA cm−2 and very high FF of 71.27% are obtained in the Alq3‐PDI2 devices, resulting in a power conversion efficiency of 9.54%, which is the best value reported for PDI‐based polymer solar cells. The coordination can also serve as a “molecular lock,” which prevents molecular motion and thus improves device stability.
Metal–Organic Framework Materials for the Separation and Purification of Light Hydrocarbons
Authors: Cui Wen‐Gang , Hu Tong‐Liang , Bu Xian‐He
Published: May 2019

The separation and purification of light hydrocarbons (LHs) mixtures is one of the most significantly important but energy demanding processes in the petrochemical industry. As an alternative technology to energy intensive traditional separation methods, such as distillation, absorption, extraction, etc., adsorptive separation using selective solid adsorbents could potentially not only lower energy cost but also offer higher efficiency. The need to develop solid materials for the efficiently selective adsorption of LHs molecules, under mild conditions, is therefore of paramount importance and urgency. Metal–organic frameworks (MOFs), emerging as a relatively new class of porous organic–inorganic hybrid materials, have shown promise for addressing this challenging task due to their unparalleled features. Herein, recent advances of using MOFs as separating agents for the separation and purification of LHs, including the purification of CH4, and the separations of alkynes/alkenes, alkanes/alkenes, C5–C6–C7 normal/isoalkanes, and C8 alkylaromatics, are summarized. The relationships among the structural and compositional features of the newly synthesized MOF materials and their separation properties and mechanisms are highlighted. Finally, the existing challenges and possible research directions related to the further exploration of porous MOFs in this very active field are also discussed.
HgTe Nanocrystal Inks for Extended Short‐Wave Infrared Detection
Authors: Martinez Bertille , Ramade Julien , Livache Clément , Goubet Nicolas , Chu Audrey , Gréboval Charlie , Qu Junling , Watkins William L. , Becerra Loïc , Dandeu Erwan , Fave Jean Louis , Méthivier Christophe , Lacaze Emmanuelle , Lhuillier Emmanuel
Published: May 2019

Short‐wave infrared (IR) detection is currently driven by InGaAs technology which has limited the perspective of cost effectiveness and consequently slows the development of IR sensors. Since organic electronics are ineffective in this wavelength range, an alternative to conductive polymers is the use of colloidal quantum dots (CQDs) which exhibit strongly tunable IR absorption. In this paper, the extended short‐wave IR (2.5 µm cut‐off) is focused on to expand the capabilities of InGaAs, while using HgTe nanocrystals as the active material. Previous devices based on this material suffer from a low responsivity due to weak absorption (few percents). The integration of HgTe nanocrystals is presented in ink form to build thick (up to 600 nm), strongly absorbing nanoparticle films. This ink is integrated into a diode, allowing one to boost the responsivity by two orders of magnitude and the detectivity by one order of magnitude compared to previous HgTe devices at the same wavelength. Detectivity reaches 3 × 109 Jones, while the time response is found to be 370 ns for room temperature and 0 V bias operation. Finally, the material is integrated into a focal plane array which is used to determine laser beam profile.
Head Start Teachers’ Professional Development, Well‐being, Attitudes, and Practices: Understanding Changes Over Time and Predictive Associations
Authors: Harding Jessica F. , Connors Maia C. , Krauss Allison Friedman , Aikens Nikki , Malone Lizabeth , Tarullo Louisa
Published: May 2019

Highlights

The professional development supports available to teachers predicted higher job satisfaction and more math activities.

Early care and education teachers’ curriculum support was related to more frequent math activities.

Early care and education teachers’ mentoring support predicted more developmentally appropriate attitudes.

Many types of professional development were not associated with teachers’ well‐being, attitudes, or practices.

Teachers’ professional development, well‐being, attitudes, and practices did not increase across cohorts.
Simultaneous determination of 75 abuse drugs including amphetamines, benzodiazepines, cocaine, opioids, piperazines, zolpidem and metabolites in human hair samples using liquid chromatography–tandem mass spectrometry
Authors: Shin Yongho , Kong Tae Yeon , Cheong Jae Cheol , Kim Jin Young , Lee Jae Il , Lee Hye Suk
Published: May 2019

A liquid chromatography–tandem mass spectrometric method for the simultaneous determination of 75 abuse drugs and metabolites, including 19 benzodiazepines, 19 amphetamines, two opiates, eight opioids, cocaine, lysergic acid diethylamide, zolpidem, three piperazines and 21 metabolites in human hair samples, was developed and validated. Ten‐milligram hair samples were decontaminated, pulverized using a ball mill, extracted with 1 mL of methanol spiked with 28 deuterated internal standards in an ultrasonic bath for 60 min at 50°C, and purified with Q‐sep dispersive solid‐phase extraction tubes. The purified extracts were evaporated to dryness and the residue was dissolved in 0.1 mL of 10% methanol. The 75 analytes were analyzed on an Acquity HSS T3 column using gradient elution of methanol and 0.1% formic acid and quantified in multiple reaction monitoring mode with positive electrospray ionization. Calibration curves were linear (r ≥ 0.9951) from the lower limit of quantitation (2–200 pg/mg depending on the drug) to 2000 pg/mg. The coefficients of variation and accuracy for intra‐ and inter‐assay analysis at three QC levels were 4.3–12.9% and 89.2–109.1%, respectively. The overall mean recovery ranged from 87.1 to 105.3%. This method was successfully applied to the analysis of 11 forensic hair samples obtained from drug abusers.
Medium Modulated Oxygen Reduction Activity of Fe/Co Active Centre‐engrafted Electrocatalysts
Authors: Kashyap Varchaswal , Anand Aljo , Soni Roby , Sreekumar Kurungot
Published: May 2019

Iron and cobalt metal atoms are effective active centers for the synthesis of carbon‐based noble‐metal‐free catalysts for the oxygen reduction reaction (ORR) owing to their cost‐effective intrinsic activity and tunable properties. Annealing of the active center with the conducting carbon enhances the ORR activity significantly. Herein, we have engrafted Fe and Co active centers in the homemade conducting carbon and the ORR performance has been closely observed under acidic and basic pH conditions to understand the influence of the medium and participating moieties towards the performance. In the half‐cell reaction, the onset potential and half‐wave potential for ORR are governed by the surface intermediates and concomitantly driven by the adsorption energies of the intermediates over the active centers. The iron and cobalt active center‐engrafted carbon catalyst behaves differently in acidic and basic electrolytes owing to the dissociation of the surface intermediates. The iron‐based catalyst shows improved onset potential against the cobalt‐based one. Similarly, the cobalt‐based catalyst shows improved half‐wave potential against the iron active‐center‐grafted catalyst. The combined synergistic effect of the two catalysts is realized in the composition represented as Fe/2Co−N‐GVC, where improved onset and half‐wave potentials are noted in basic medium. A significant variation in the activity of the catalyst is observed as the medium changes from acidic to basic and the effect is directly associated with the surface adsorption of the intermediates.
New Dyes Based on Extended Fulvene Motifs: Synthesis through Redox Reactions of Naphthoquinones with Donor–Acceptor Cyclopropanes and Their Spectroelectrochemical Behavior
Authors: Lücht Alexander , Sobottka Sebastian , Patalag Lukas J. , Jones Peter G. , Reissig Hans‐Ulrich , Sarkar Biprajit , Werz Daniel B.
Published: May 2019

Novel dyes based on extended fulvene motifs are reported. The carbon skeleton was generated by a catalyzed addition of donor–acceptor cyclopropanes to naphthoquinone. The hydroxy group at the central ring of the tricyclic fulvene motif was converted into the triflate, which reacted efficiently with a wide range of nucleophiles, resulting in substitution and thereby providing new derivatives. The synthetic versatility allowed us to investigate the absorption, electrochemical, and UV/Vis‐NIR spectroelectrochemical properties of these dyes as a function of the substituents. The dyes were shown to participate in reductive electrochemistry, the reversibility of which can be improved by appropriate selection of the substituents. Additionally, first signs of NIR electrochromism are presented, opening new avenues for the future investigations of such dyes.
Novel Bifunctionalization of Activated Methylene: Base‐Promoted Trifluoromethylthiolation of β‐Diketones with Trifluoromethanesulfinyl Chloride
Authors: Sun Dong‐Wei , Jiang Min , Liu Jin‐Tao
Published: May 2019

A novel bifunctionalization of activated methylene was achieved successfully through the base‐promoted trifluoromethylthiolation of β‐diketones or β‐ketoesters with trifluoromethanesulfinyl chloride. A series of α‐trifluoromethylthiolated α‐chloro‐β‐diketones and α‐chloro‐β‐ketoesters were obtained in moderate to good yields under mild conditions. When β‐diketones containing a phenyl group with a hydroxyl or amino substituent at the ortho position were used as substrates, intramolecular trifluoromethylthiolation/cyclization reaction took place to give the corresponding cyclic products. Furthermore, the protocol could be extended to perfluoroalkylthiolation with the sodium perfluoroalkanesulfinate/POCl3 system. On the basis of experimental results, plausible mechanisms are proposed.
Risk of malignancy associated with cytomorphology subtypes in the salivary gland neoplasm of uncertain malignant potential (SUMP) category in the Milan System: A bi‐institutional study
Authors: Chowsilpa Sayanan , An Daniel , Lose Holly , Huang Xiao , Nayar Ritu , Maleki Zahra
Published: May 2019

Background

Salivary gland neoplasm of uncertain malignant potential (SUMP) is a diagnostic category in the Milan System for Reporting Salivary Gland Cytopathology. The objective of this study was to assess the risk of neoplasm (RON) and the risk of malignancy (ROM) in SUMP cases by evaluating them based on their prominent cytomorphology.

Methods

The pathology databases were searched for cases of fine‐needle aspiration–diagnosed SUMP at The Johns Hopkins Hospital and Northwestern University from 2013 to 2018. Only cytopathology cases diagnosed as SUMP that had available surgical follow‐up were included.

Results

Sixty‐five patients with SUMP were identified, including 31 men and 34 women who ranged in age from 15 to 87 years (mean age, 55.2 years). Sixty‐five cases had histologic follow‐up, including 13 (20%) with basaloid features, 13 (20%) with oncocytic features, and 39 (60%) with unspecified features. No cases with clear cell features were found. Overall, the RON in the SUMP category was 95.4% (62 of 65 cases), and the ROM was 33.8% (22 of 65 cases). The RON in SUMPs with basaloid, oncocytic, and unspecified subtypes was 92.3%, 100%, and 94.9%, respectively, whereas the ROM was 38.5%, 7.7%, and 41%, respectively. The most common benign neoplasm was pleomorphic adenoma (23.1%), whereas mucoepidermoid carcinoma (9.2%) was the most common malignant neoplasm.

Conclusions

This study shows that the ROM differs significantly based on cytomorphology subtypes, whereas the overall ROM is approximately the same as the target rate in the Milan System for Reporting Salivary Gland Cytopathology. Moreover, the RON remains high in the SUMP category among different cytomorphology subtypes. Adequate sampling, immunohistochemical staining, and familiarity with metaplastic and reactive changes may improve the diagnosis.
Structural Phase Transitions in Niobium Hydrogen Thin Films: Mechanical Stress, Phase Equilibria and Critical Temperatures
Authors: Wagner Stefan , Klose Philipp , Burlaka Vladimir , Nörthemann Kai , Hamm Magnus , Pundt Astrid
Published: May 2019

Metal−hydrogen (M−H) systems offer grand opportunities for studies on fundamental aspects of thermodynamics and kinetics. When the system size is reduced to the nanoscale, microstructural defects as well as mechanical stress affect the systems’ properties. This is contemplated for the model system of epitaxial niobium−hydrogen (Nb−H) thin films. Hydrogen absorption in metals commonly leads to lattice expansion which is hindered when the metal adheres to a flat rigid substrate. Consequently, high mechanical stress of about −10 GPa for 1 H/Nb are predicted, in theory. However, metals cannot yield such high stresses and respond with plastic deformation, commonly limiting measured stresses to −2 to −3 GPa for 100 nm Nb−H films. It will be shown that the coherency state changes with film thickness reduction, shifting the onset of plastic deformation to larger hydrogen concentrations. Below critical film thicknesses, plastic deformation is fully absent. The system then behaves purely elastic and ultra‐high stress of about −10 (±2) GPa can be obtained. Arising stress controls the phase stability of M−H systems, and the coherency state strongly affects the nucleation and growth dynamics of the phase transition. In case of Nb−H thin films of less than 8 nm thickness the common phase transformation from the α‐phase solid solution to the hydride phase is completely suppressed at 300 K. Related effects can be utilised to optimise metal−hydrides used in applications.
Honeycomb‐Inspired Surface‐Patterned Cu@CuO Composite Current Collector for Lithium‐Ion Batteries
Authors: Yuan Wei , Qiu Zhiqiang , Huang Yao , Wang Chun , Huang Honglin , Yang Yang , Zhang Xiaoqing , Luo Jian , Tang Yong
Published: May 2019

The interface design between the current collector and active materials has a non‐negligible effect on the performance of lithium‐ion batteries (LIBs). Inspired by the honeycomb with a large specific surface area, this work validates the use of a surface‐patterned cellular Cu@CuO composite current collector with a hexagonal blind hole array and a nanostructured film of CuO nanoflowers for LIBs. This unique structure is synthesized by lithography and solution immersion. Mesocarbon microbead graphite powders are used as the active materials. Results show that the battery with the cellular Cu@CuO current collector maintains a reversible charge capacity of 354.1 mAh g−1 at 100 mA g−1 after 200 cycles. Compared with the Cu‐based current collector with a hexagonal blind hole array and a bare Cu current collector, the new pattern gains a performance improvement in the reversible capacity by 27.9% and 153.2%, respectively. The excellent electrochemical property of the cellular Cu@CuO current collector can be ascribed to strengthened adhesion with the active materials, reduced contact resistance, and improved Li‐ion diffusion capability. Due to the enhanced electrochemical performance, facile preparation processes, and cost‐effective raw materials, the new current collector shows great potential to replace the conventional current collector of energy storage systems.
A prospective study of dairy product intake and the risk of hepatocellular carcinoma in U.S. men and women
Authors: Yang Wanshui , Sui Jing , Ma Yanan , Simon Tracey G. , Chong Dawn , Meyerhardt Jeffrey A. , Willett Walter C. , Giovannucci Edward L. , Chan Andrew T. , Zhang Xuehong
Published: May 2019

Although increasing dairy product intake has been associated with risk of several cancers, epidemiological studies on hepatocellular carcinoma are sparse and have yielded inconsistent results. We prospectively assessed the associations of dairy products (total, milk, butter, cheese and yogurt) and their major components (calcium, vitamin D, fats and protein) with the risk of hepatocellular carcinoma development among 51,418 men and 93,427 women in the Health Professionals Follow‐Up Study and the Nurses' Health Study. Diets were collected at baseline and updated every 4 years using validated food frequency questionnaires. Multivariable hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated using Cox proportional hazards regression model. During up to 32 years of follow‐up, a total of 164 hepatocellular carcinoma cases were documented. After adjustment for most known hepatocellular carcinoma risk factors, higher total dairy product intake was associated with an increased risk of hepatocellular carcinoma (highest vs. lowest tertile, HR = 1.85, 95% CI: 1.19–2.88; ptrend = 0.009). For the same comparison, we observed significant positive associations of high‐fat dairy (HR = 1.81, 95% CI: 1.19–2.76; ptrend = 0.008) and butter (HR = 1.58, 95% CI: 1.06–2.36; ptrend = 0.04) with hepatocellular carcinoma risk. There was a nonsignificant inverse association between yogurt intake and hepatocellular carcinoma risk (HR = 0.72, 95% CI: 0.49–1.05; ptrend = 0.26). Our data suggest that higher intake of high‐fat dairy foods was associated with higher, whereas higher yogurt consumption might be associated with lower risk of developing hepatocellular carcinoma among U.S. men and women.
Clinical significance of BPI‐ANCA detecting in COPD patients with Pseudomonas aeruginosa colonization
Authors: Tian Yongjian , Zeng Tingting , Tan Liming , Wu Yang , Yu Jianlin , Huang Jiayi , Pei Zihuang
Published: May 2019

Background

Antineutrophil cytoplasmic autoantibodies against neutrophil granule bactericidal/permeability‐increasing protein (BPI‐ANCA) has been found in many inflammatory diseases, such as COPD, which can reduce the killing effect of BPI on Gram‐negative bacteria. This study was aimed to assess the clinical significance of BPI‐ANCA detecting in COPD patients with Pseudomonas aeruginosa (P aeruginosa) colonization.

Methods

A total of 216 COPD patients with lung P aeruginosa colonization, 244 patients with P aeruginosa infection from June 2015 to June 2018, and 100 healthy individuals were included. Serum BPI‐ANCA, tumor necrosis factor (TNF)‐α, and interleukin (IL)‐6 and IL‐1β levels were detected by ELISA, and the lung function of the patients was measured at stable clinical stages. Patients with COPD were grouped according to BPI‐ANCA detection and GOLD criteria, and serum TNF‐α, IL‐6, and IL‐1β levels and indices reflecting lung function were compared and analyzed between groups.

Results

Positive rate of BPI‐ANCA in COPD patients with P aeruginosa colonization was 48.15%; and compared with BPI‐ANCA(‐) group, FEV1%pred and FEV1/FVC(%) in BPI‐ANCA(+) patients were significantly decreased, while TNF‐α, IL‐6, and IL‐1β levels were elevated. There were 31.73% and 36.54% BPI‐ANCA(+) patients with severe and very severe airflow limitation, respectively, which was significantly higher than that in the BPI‐ANCA(‐) group. FEV1%pred and FEV1/FVC(%) were negatively correlated with TNF‐α, IL‐6, IL‐1β, and NEU%. C‐reactive protein (CRP) was negatively correlated with FEV1%pred, yet not significantly correlated with FEV1/FVC(%).

Conclusion

BPI‐ANCA positivity is associated with inflammatory status in COPD patients with pulmonary P aeruginosa colonization and can be used as a potential biomarker assessing disease severity.
Manganese in PET imaging: Opportunities and challenges
Authors: Brandt Marie , Cardinale Jens , Rausch Ivo , Mindt Thomas L.
Published: May 2019

Several radionuclides of the transition metal manganese are known and accessible. Three of them, 51Mn, 52mMn, and 52gMn, are positron emitters that are potentially interesting for positron emission tomography (PET) applications and, thus, have caught the interest of the radiochemical/radiopharmaceutical and nuclear medicine communities. This mini‐review provides an overview of the production routes and physical properties of these radionuclides. For medical imaging, the focus is on the longer‐living 52gMn and its application for the radiolabelling of molecules and other entities exhibiting long biological half‐lives, the imaging of manganese‐dependent biological processes, and the development of bimodal PET/magnetic resonance imaging (MRI) probes in combination with paramagnetic natMn as a contrast agent.
Effects of omega‐3 fatty acids and aspirin on Porphyromonas gingivalis‐induced periodontitis in rats
Authors: Yang Ming , Li Liang , Soh Yunjo , Heo Seok‐Mo
Published: May 2019

Background

Periodontitis is a common chronic inflammatory disease caused by bacteria which can result in periodontal tissue inflammation, as well as alveolar bone resorption. The purpose of this study was to evaluate the effects of omega‐3 fatty acids plus aspirin (ASA) on ligature‐induced periodontitis in rats.

Methods

Ninety‐six male Sprague‐Dawley (SD) rats (age 6 weeks) were randomly divided into eight groups (n = 12 each) and had ligatures placed for 7 days, followed by daily treatment with specific drug regimens for 14 days. The rats were sacrificed 20 days after drug treatment, and their maxillary were subjected to histomorphometric analysis. RAW264.7 cells were cultured with lipopolysaccharide (LPS) or receptor activator (NF)‐κB ligand (RANKL), and treated with various concentrations of omega‐3 and ASA. Then, cyclooxygenase (COX‐2), inducible nitric oxide synthase (iNOS) protein expression and receptor activator of nuclear factor κ B (RANK), tartrate‐resistant acid phosphatase (TRAP), matrix metalloproteinase‐9 (MMP‐9), MMP‐2, and Cathepsin‐K gene expression were detected.

Results

The administration of omega‐3 fatty acids and aspirin significantly inhibited tumor necrosis factor‐α (TNF‐α) and interleukin‐1β (IL‐1β) in serum of rats. Histomorphometric analysis showed omega‐3 fatty acids plus aspirin promoted alveolar bone increase. Omega‐3 fatty acids only, aspirin only, or omega‐3 fatty acids plus aspirin also inhibited the protein expressions of COX‐2 and iNOS in LPS‐stimulated RAW264.7 cells. In addition, omega‐3 combined with ASA also inhibited the RANKL‐induced gene expressions of MMPs in dose‐dependent manners.

Conclusion

These results demonstrate that omega‐3 fatty acids plus aspirin could decrease alveolar bone loss, while simultaneously increasing the protection against periodontal inflammation.
Mathematical analysis of the motion of a rigid body in a compressible Navier–Stokes–Fourier fluid
Authors: Haak Bernhard H. , Maity Debayan , Takahashi Takéo , Tucsnak Marius
Published: May 2019

We study an initial and boundary value problem modelling the motion of a rigid body in a heat conducting gas. The solid is supposed to be a perfect thermal insulator. The gas is described by the compressible Navier–Stokes–Fourier equations, whereas the motion of the solid is governed by Newton's laws. The main results assert the existence of strong solutions, in an ‐ setting, both locally in time and globally in time for small data. The proof is essentially using the maximal regularity property of associated linear systems. This property is checked by proving the ‐sectoriality of the corresponding operators, which in turn is obtained by a perturbation method.
Geographical distribution of Vip3Aa20 resistance allele frequencies in Spodoptera frugiperda (Lepidoptera: Noctuidae) populations in Brazil
Authors: Amaral Fernando S A , Guidolin Aline S , Salmeron Eloisa , Kanno Rubens H , Padovez Fernando E O , Fatoretto Júlio C , Omoto Celso
Published: May 2019

BACKGROUND

The use of Bt plants has been the main strategy for controlling the fall armyworm Spodoptera frugiperda (J. E. Smith) in Brazil. However, many resistance cases were already registered. The resistance of S. frugiperda to the Vip3Aa20 protein was recently characterized under laboratory conditions but it is still efficient under field conditions. Here, resistance monitoring studies were conducted using phenotypic (purified protein and Bt maize leaves) and genotypic (F1 and F2 screen) methods to support insect resistance management (IRM) programs and preserve Vip3Aa20 technology on maize.

RESULTS

Phenotypic monitoring with purified protein showed two populations significantly different from the susceptible strain on the second crop season in 2016. This number increased for the first and second crop seasons in 2017 in several regions. The genotypic monitoring estimated a mean frequency of the resistance allele of 0.0027 for the F1 screen and 0.0033 for the F2 screen. Three new resistant strains to Vip3Aa20 were selected from F2 screen assays. Complementation tests on these new resistant strains were positive with the previous resistant strain.

CONCLUSION

Here we showed that the resistance allele of S. frugiperda to Vip3Aa20 protein is widely distributed in maize‐producing regions in Brazil and its frequency increases throughout crop seasons. © 2019 Society of Chemical Industry