bluuebunny/crossref_metadata_2025 huggingface dataset:
Genetische Ursachen und Therapie der Osteogenesis imperfecta
Authors: Semler Oliver , Kornak Uwe , Oheim Ralf , Seefried Lothar
Published: September 2020

Die Osteogenesis imperfecta (OI) ist die häufigste angeborene Erkrankung, die zu einer erhöhten Fragilität des Skelettsystems führt. Die Variabilität des Phänotyps kann nicht vollständig durch die ursächlichen genetischen Veränderungen erklärt werden. Die meisten Formen werden durch Mutationen in Genen verursacht, die die Kollagen-Synthese/-Prozessierung verändern, wobei die meisten Patientinnen und Patienten von Mutationen in den Genen COL1A1/A2 betroffen sind. Das bessere Verständnis der Pathophysiologie bei seltenen rezessiven Formen der Erkrankung hat bereits in zwei Fällen zu neuen therapeutischen Ansätzen geführt. Bei OI Typ VI, verursacht durch Mutationen in SERPINF1, kommt es zu einer Überaktivierung von Osteoklasten über den OPG/RANKL-pathway. Hier konnte gezeigt werden, dass eine Behandlung mit dem Osteoklasten-Antikörper Denosumab effektiver ist als eine antiresorptive Therapie mit Bisphosphonaten. Bei Patientinnen und Patienten, bei denen die ursächliche Mutation im Gen WNT1 liegt, bietet sich eine osteoanabole Behandlung mit Antisklerostin-Antikörpern an. Neben der medikamentösen Therapie sind die Bereiche der Rehabilitation und Orthopädie unverzichtbare Bestandteile einer interdisziplinären Behandlung.
The Potential Therapeutic Role of Proton Pump Inhibitors in COVID-19:
Hypotheses Based on Existing Evidences
Authors: Ray Avik , Sharma Swati , Sadasivam Balakrishnan
Published: September 2020

Although the major therapeutic uses of the proton pump inhibitors are in
gastric-acid related diseases, evidences are suggestive of a pleiotropic nature
of the compounds. We comment on the probable pathways and cellular machineries
via which proton pump inhibitors could show beneficial therapeutic effects
against SARS-CoV-2 based on the existing evidences. Proton pump inhibitors have
shown antiviral potencies in various in vivo and in vitro studies. Some of the
major possible ways through which they can act against SARS-CoV-2 are by
exerting anti-inflammatory and anti-fibrotic effects, via vacuolar ATPase pumps
leading to raised endolysosomal pH and by targeting endosomal complexes. The
current pandemic has put forward a challenge to find treatment options. Although
the potential roles of proton pump inhibitors against SARS-CoV-2 have been
discussed in recent publications, the clinical evidences for their real-world
effectiveness do not point towards a beneficial effect clearly yet. We suggest
that although proton pump inhibitors should strongly be considered as potential
therapeutic options for COVID-19, larger studies in the form of randomized
controlled trials would be required to arrive at a definite conclusion.
Transition-Metal-Free Synthesis of Trifluoromethylated Furans via a Bu3P-Mediated Tandem Acylation–Wittig Reaction
Authors: Zhou Wei , Li Maizhan
Published: September 2020

A highly efficient nucleophilic addition–O-acylation–intramolecular Wittig reaction of β-trifluoromethyl α,β-enones is disclosed. This strategy features mild reaction conditions and provides a practical transition-metal-free method to a set of biologically significant trifluoromethylated furans in high yields with diverse functional groups.
The Role of ROCK in Platelet–Monocyte Collaborative Induction of Thromboinflammation during Acute Coronary Syndrome
Authors: Hsu Ling-Wei , Chen Po-Wei , Chang Wei-Ting , Lee Wen-Huang , Liu Ping-Yen
Published: September 2020

Background Arterial thrombosis is initiated by atherosclerotic plaque damage, prothrombotic material release and platelet aggregation. Platelets are primary mediators involved in thrombosis and cooperate with vascular and immune cells.

Objective Herein, we investigated how activated platelets interacted with monocytes in atherothrombosis.

Methods and Results We collected patients' blood from coronary arteries during percutaneous coronary intervention and measured platelet activity. Platelets from coronary arteries had higher pseudopodium expression and activity in patients with acute coronary syndrome (ACS). Ribosome profiling of platelets from coronary blood mapped a vigorous upregulation of Rho GTPases and their downstream effectors. RhoA activated downstream Rho-associated coiled-coil containing protein kinase (ROCK), and ROCK increased surface P-selectin in coronary blood platelets. The interaction between platelets and monocytes was observed in vitro, and was found in ruptured coronary plaques of ACS. Further we found that activated platelets promoted monocytes transmigration, which could be suppressed in the presence of ROCK inhibitors. The increased surface P-selectin on thrombin-induced platelets interacted with monocytes to upregulate monocyte chemokine receptor 2 (CCR2) expression via the ROCK pathway. The expression of CCR2 was higher in monocyte–platelet aggregates than in monocytes without platelets. Finally, using the Asian Screening Array BeadChip, we identified single-nucleotide polymorphism (SNP) associated with cardiovascular events. Notably, patients having homozygous major alleles of the RHOA SNP rs11706370 presented with higher risks of cardiovascular events.

Conclusion Through ROCK-activated cytoskeleton remodeling and P-selectin expression, platelets were recruited and interacted synergistically with high CCR2-expressing monocytes to induce thromboinflammation in atherothrombosis.
Monitoring DOACs with a Novel Dielectric Microsensor: A Clinical Study
Authors: Maji Debnath , Opneja Aman , Suster Michael A. , Bane Kara L. , Wilson Brigid M. , Mohseni Pedram , Stavrou Evi X.
Published: September 2020

Background There are acute settings where assessing the anticoagulant effect of direct oral anticoagulants (DOACs) can be useful. Due to variability among routine coagulation tests, there is an unmet need for an assay that detects DOAC effects within minutes in the laboratory or at the point of care.

Methods We developed a novel dielectric microsensor, termed ClotChip, and previously showed that the time to reach peak permittivity (T
peak) is a sensitive parameter of coagulation function. We conducted a prospective, single-center, pilot study to determine its clinical utility at detecting DOAC anticoagulant effects in whole blood.

Results We accrued 154 individuals: 50 healthy volunteers, 49 rivaroxaban patients, 47 apixaban, and 8 dabigatran patients. Blood samples underwent ClotChip measurements and plasma coagulation tests. Control mean T
peak was 428 seconds (95% confidence interval [CI]: 401–455 seconds). For rivaroxaban, mean T
peak was 592 seconds (95% CI: 550–634 seconds). A receiver operating characteristic curve showed that the area under the curve (AUC) predicting rivaroxaban using T
peak was 0.83 (95% CI: 0.75–0.91, p < 0.01). For apixaban, mean T
peak was 594 seconds (95% CI: 548–639 seconds); AUC was 0.82 (95% CI: 0.73–0.91, p < 0.01). For dabigatran, mean T
peak was 894 seconds (95% CI: 701–1,086 seconds); AUC was 1 (p < 0.01). Specificity for all DOACs was 88%; sensitivity ranged from 72 to 100%.

Conclusion This diagnostic study using samples from “real-world” DOAC patients supports that ClotChip exhibits high sensitivity at detecting DOAC anticoagulant effects in a disposable portable platform, using a miniscule amount of whole blood (<10 µL).
Pseudotumor Cerebri Caused by SARS-CoV-2 Infection in a Boy
Authors: Soto Insuga Victor , Cantarín-Extremera Verónica , Solís-Muñoz Inés , Buendía-Martínez Silvia , Atencia-Ballesteros María , Bernardino Beatriz , Ruiz Falcó María Luz
Published: September 2020

In this case report, we present the case of a 7-year-old male patient who started with diplopia and paralysis of the sixth unilateral cranial nerve after a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. The cranial resonance was normal and the cerebrospinal pressure was 32 cm H2O detected by lumbar puncture. The treatment with corticosteroids and acetazolamide was effective. This is the first case of idiopathic intracranial hypertension associated to SARS-CoV-2 probably due to immune-mediated process.
Fluoroquinolone Resistance in Clinical Isolates of Klebsiella Pneumoniae
Authors: Geetha Pacha Venkataramana , Aishwarya Kayanam Vijaya Lalitha , Mariappan Shanthi , Sekar Uma
Published: September 2020

Introduction Fluoroquinolones are widely used broad-spectrum antibiotics. Recently, increased rate of resistance to this antibiotic has been observed in Klebsiella pneumoniae. The aim of the present study was to determine the presence of quinolone resistance determining regions (QRDR) mutation genes and plasmid-mediated quinolone resistance (PMQR) determinants in clinical isolates of ciprofloxacin-resistant K. pneumoniae.

Material and Methods The study included 110 nonduplicate ciprofloxacin-resistant K. pneumoniae clinical isolates. Antibiotic susceptibility testing by disk diffusion method and minimum inhibitory concentration (MIC) by agar dilution methods for ciprofloxacin was performed according to the recommendations of Clinical Laboratory Standards Institute. The presence of QRDR genes and PMQR genes was screened by polymerase chain reaction (PCR) amplification.

Result All 110 isolates were resistance to ciprofloxacin, levofloxacin, and ofloxacin. As much as 88% of the isolates exhibited high-level of MIC to ciprofloxacin. Among the 110 isolates, 94(85%) harbored gyrA and 85 (77%) gyrB. The parC and parE genes were detected in 88 (80%) and 64 (58%) isolates. qnrB was detected in 13 (12%) isolates and qnrS in 5 (4.5%) isolates. Two (1.8%) isolates carried both qnrB and qnrS genes. The acc (6')-Ib-cr gene was found in 98 (89%) isolates and oqxAB was detected in 7 (6.3%) isolates. One (0.9%) isolate carried qnrB, acc(6')-Ib-cr and oqxAB genes.

Conclusion The prevalence of acc (6')-Ib-cr gene is high among PMQR determinants, followed by qnrB, oqxAB and qnrS.
Genetic Diversity of Human Immunodeficiency Virus Type 1 in Asymptomatic Blood Donors in Islamabad, Pakistan
Authors: Waheed Usman , Noor Farooq Ahmed , Saba Noore , Wazeer Akhlaaq , Qasim Zahida , Arshad Muhammad , Karimi Saira , Farooq Ahmad , Usman Javaid , Zaheer Hasan Abbas
Published: September 2020

Objective The serological testing of human immunodeficiency virus (HIV) is mandatory under the blood safety legislation of Pakistan; hence, data exist on the prevalence of HIV in blood donors. However, little is known about the molecular epidemiology of HIV in the blood donor population. Therefore, the current study was designed to study the genetic diversity of HIV-1 infection in a population of apparently healthy treatment-naive blood donors in Islamabad, Pakistan.

Material and Methods A total of 85,736 blood donors were tested for HIV by the chemiluminescence immunoassay. All positive donor samples were analyzed for the presence of various HIV genotypes (types and subtypes). Viral ribonucleic acid was extracted from blood samples of HIV positive donors and reverse transcribed into complementary deoxyribonucleic acid (cDNA). The cDNA of all positive donors was then analyzed for the presence of various HIV genotypes (types and subtypes) by employing subtype-specific primers in a nested polymerase chain reaction. The amplified products were run on ethidium bromide-stained 2% agarose gel and visualized using a ultraviolet transilluminator. A particular subtype was assigned to a sample if the subtype-specific reaction made a band 20% highly intense compared with the band made by the subtype-independent reaction.

Results A total of 85,736 blood donors were screened for the presence of antibodies to HIV. Out of them, 114 were initially found reactive for HIV. The repeat testing resulted in 112 (0.13%) positive donors, 95% confidence interval 0.0014 (0.0011–0.0018). These 112 samples were analyzed for molecular typing of HIV-1. The predominant HIV-1 subtype was A (n = 101) (90.1%) followed by subtype B (n = 11) (9.9%).

Conclusion These findings are key to understand the diversified HIV epidemic at the molecular level and should assist public health workers in implementing measures to lessen the further dissemination of these viruses in the country.
Assessment of India's energy dynamics: Prospects of solar energy
Authors: Irfan Muhammad , Zhao Zhen-Yu , Ikram Muhammad , Gilal Naeem Gul , Li Heng , Rehman Abdul
Published: September 2020

During the last decade, energy demand has increased manifold in India. To cope up with the rising energy demand, the Indian government has announced the National Solar Mission to generate 100 GW solar power by 2022. Large-scale solar power developers have been allotted around 60% of the National Solar Mission target. Therefore, it becomes pivotal to find the ground reality of solar power developers. To fulfill this objective, we selected the solar sources of the country and adopted a hybrid research methodology. The solar irradiation data were collected for one year in the four big cities of India, Mumbai, New Delhi, Chennai, and Bangalore during 2019 to evaluate the efficiency of photovoltaics (PVs). MATLAB and RETScreen were employed for data analysis and evaluating the efficiency of photovoltaics. We take this a step further by performing the Life Cycle Assessment analysis to scrutinize the different features of solar energy, including fuel consumption, price, average lifetime, maintenance and operation expenses, land requirements, and greenhouse gas emissions. The results reveal that all these cities have an enormous solar power potential, as they are located in an area where solar irradiations are consistently available all over the year (except for monsoon season). Moreover, solar energy is more durable, cost-saving, and easy to maintain. Furthermore, we identified the significant barriers over the whole solar energy spectrum by conducting semi-structured interviews with industry experts. These barriers are broadly classified into technological, policy, regulatory, financial, transparency, accountability, infrastructural, and trade policy categories. Finally, essential policy recommendations have been suggested for all stakeholders in order to fulfill the country's energy demand on its way to a future of sustainable development.
Effects of the working parameters on the flow-field numerical results for a medium-power ICP wind tunnel
Authors: Yu Minghao , Li Yiwen , Wang Zhe , Chen Ge , Wei Xiaolong
Published: September 2020

Numerical simulations of subsonic and supersonic nonequilibrium air inductively coupled plasmas (ICPs) were carried out inside a medium-power 100-kW ICP wind tunnel (ICPWT), which is widely used to study the thermal protection system and the blackout phenomenon of reentry vehicles in the aerospace field. A thermochemical nonequilibrium magneto-hydrodynamic numerical model, which takes into account the coupling of Navier–Stokes equations, electromagnetic-field equations, the four-temperature model, and the 32 chemical reactions of air, was constructed and applied. Basic flow characteristics of the inductive plasma, such as the hot plasma flame beneath the inductive coil, the subsonic-supersonic transition in the conical nozzle, and the vortexes in the torch and in the vacuum chamber, were reproduced successfully. Additionally, the effects of different working parameters (e.g., number of coil turns, mass-flow rate, working pressure, and radius of the discharge tube) of the ICPWT on its flow-field properties were numerically investigated. The numerical results demonstrated that atomic N and O are the most dominant chemical components at the coil center. Five turns of the inductive coil is optimal for this medium-power ICPWT.
Inverse and direct magnetoelectric effects in orthorhombic DyMnO3 manganite single crystals
Authors: Freidman A. L. , Semenov S. V. , Kolkov M. I. , Terent'ev K. Yu. , Pavlovskiy N. S. , Gokhfeld D. M. , Shaykhutdinov K. A. , Balaev D. A.
Published: September 2020

Correlations between the direct and inverse magnetoelectric effects in orthorhombic DyMnO3 single crystals have been investigated. In the inverse magnetoelectric effect, the magnetic moment of the crystal appears to have a contribution that is sinusoidal oscillating in ac electric fields below the temperature TFE of ferroelectric phase transition. The first and the second harmonics of the inverse magnetoelectric effect are clearly detected. The magnetoelectric susceptibilities α and β, corresponding to first and second harmonics, are found to correlate with the derivative of polarization with respect to the magnetic field. The influence of the magnetic and electric regimes during cooling on magnetoelectric effects has also been studied. The maximum change in the magnetic moment of a sample under the action of electric fields is observed under the same (T, H) conditions as the rotation of the spontaneous polarization vector from the crystallographic c direction to the a axis in the magnetic field H || b.
Interplay between coherence-time undersampling and scattered light in two-dimensional electronic spectroscopy
Authors: Dostál Jakub , Alster Jan
Published: September 2020

Scanning pulse delays in multi-pulse non-linear optical spectroscopy experiments is a major contributor to lengthy data acquisition. Using large steps for the scan can significantly speed up the experiment. However, an improper choice of step length can cause distortions to the resulting spectra, especially if the light scattered on the sample is mixed into the signal. In this work, we identify potential sources of such distortions and suggest appropriate countermeasures to avoid them while maintaining a faster data collection.
Time synchronization and data transfer method for towed electromagnetic receiver
Authors: Qiu Yong , Yang Qin , Deng Ming , Chen Kai
Published: September 2020

Deep marine controlled-source electromagnetic (CSEM) prospecting has attracted extensive interest because it enables high efficiency and high horizontal-resolution prospecting of gas hydrate and oil. However, the elimination of time errors between the transmitter and the receiver and realization of long-distance high-speed real-time data transmission (submarine towed body status information and raw electromagnetic field data stream) are worthwhile challenges that require continuous effort. We developed a novel towed CSEM system using double-vessels that have high time synchronization accuracy and real-time data transmission. The near-seafloor-towed CSEM receiver contains a deck user terminal, master node, slave nodes, tail buoy, and neutrally buoyant towed cable. The deck user terminal generated and transmitted a pulse per second to the master node through a fiber converter and optical fiber. The RS-485 transceiver then turned the pulse signal into a differential signal and transmitted it to each slave node for error-free synchronization. The time information was also transmitted from the deck user terminal to various nodes through ethernet switches, optical fibers, and serial to ethernet converters. The deck user terminal can conveniently communicate with each node cascaded by the ethernet switch through ethernet and fiber optic communication technology. During an offshore experiment involving oil and gas exploration in the South China Sea, the towed CSEM receiver continuously acquired all electromagnetic components and status information, which achieved a preliminary prospecting result. The maximum transfer rate of real-time data can reach 10 Mbps with 300 m distance between each slave node, and the time synchronization error between transmitter and receiver is less than ±3 µs.
Quantitative detection of thermal barrier coating parameters based on electromagnetic/capacitive dual modality sensor
Authors: Wang Wei , Chen Dixiang , Liu Lihui , Zhou Weihong , Qiu Xiaotian , Ding Qiaochu , Ren Yuan , Hu Jiafei , Zhang Qi , Pan Mengchun
Published: September 2020

A thermal barrier coating (TBC), which is composed of a top coating (TC) and bond coating (BC), can keep a turbine engine working in high temperature. The TC is an insulated ceramic layer, and the BC is a conductive layer between the TC and engine blade. Owing to poor working conditions, some failures such as sintering, thinning of coating thickness, and oxide layer initiation will occur in the TBC. Once any part of the TBC fails, it will seriously threaten the safety of the aircraft. The quantitative detection of TBC parameters is realized with the electromagnetic/capacitive dual modality sensor in this paper. The measurement grid algorithm is used to inverse the thickness of the TC layer and the conductivity of the BC layer, and an analytical method is proposed to inverse the relative permittivity of the TC layer. According to the experiment, the inversion errors of these parameters are all less than 4%, which can meet the industry needs well.
A Fermi smearing variant of the Tamm–Dancoff approximation for nonadiabatic dynamics involving S1–S transitions: Validation and application to azobenzene
Authors: Peters Laurens D. M. , Kussmann Jörg , Ochsenfeld Christian
Published: September 2020

The main shortcoming of time-dependent density functional theory (TDDFT) regarding its use for nonadiabatic molecular dynamics (NAMD) is its incapability to describe conical intersections involving the ground state. To overcome this problem, we combine Fermi smearing (FS) DFT with a fractional-occupation variant of the Tamm–Dancoff approximation (TDA) of TDDFT in the generalized gradient approximation. The resulting method (which we denote as FS-TDA) gives access to ground- and excited-state energies, gradients, and nonadiabatic coupling vectors, which are physically correct even in the vicinity of S1–S0 conical intersections. This is shown for azobenzene, a widely used photoswitch, via single point calculations and NAMD simulations of its cis–trans photoisomerization. We conclude that FS-TDA may be used as an efficient alternative to investigate these processes.
Ferroelectric and dielectric properties of improper ferroelectric Ca8−xSrx[Al12O24 ](MoO4)2 multilayer capacitors
Authors: Hirose Sakyo , Usui Tomoyasu , Tanaka Masahiko , Katsuya Yoshio , Taniguchi Hiroki
Published: September 2020

Improper ferroelectric Ca8−xSrx[Al12O24](MoO4)2 (x = 0–2) multilayer capacitors (MLCs) were fabricated to study their dielectric and ferroelectric properties for their potential practical applications and reversible switching of electric polarization by an electric field. The substitution of Sr for Ca caused a structural change from polar orthorhombic to non-polar cubic phases at 297 K and decreased the ferroelectric phase transition temperature (Tc). Spontaneous polarization up to ∼0.6 μC/cm2 was performed at 297 K in Ca7.5Sr0.5[Al12O24](MoO4)2 and Ca7Sr[Al12O24](MoO4)2 MLCs by poling with an electric field of 10 MV/m. Furthermore, ferroelectric hysteresis loops from the electric polarization switching were successfully demonstrated in Ca8[Al12O24](MoO4)2 MLCs above 469 K by the application of a high electric field over 50 MV/m, and remnant electric polarization of ∼0.59 μC/cm2 was obtained at 573 K. The results introduce a new avenue for possible applications and new functionalities of improper ferroelectrics with an MLC structure.
Visible-to-near-infrared organic photodiodes with performance comparable to commercial silicon-based detectors
Authors: Song Yu , Yu Gang , Xie Boming , Zhang Kai , Huang Fei
Published: September 2020

Photodetection in the visible and near-infrared (NIR) spectral regions offers a wide range of applications, such as image arrays of high pixel density and artificial intelligence. In this work, broadband organic photodiodes (OPDs) are developed with performance comparable to that of crystalline silicon-based commercial devices. Through the strategy of combining an NIR-absorbing non-fullerene acceptor and a thick junction, the resulting devices show significantly improved performance parameters, with a suppressed dark current density of 0.35 nA/cm2, an enhanced spectral response covering 300–1000 nm, and external quantum efficiency over 60% el/ph. Owing to the low dark current noise and high responsivity to NIR wavelengths, an unexpectedly high specific detectivity of 5.1 × 1013 Jones at 930 nm is obtained together with a linear dynamic range of 157  dB and a −3  dB cutoff frequency of 4.5  kHz. These results reveal that the NIR OPD has great potential for 2D and 3D imaging applications with a high frame rate and multiple band selection.
The effect of column-shaped discharge duration on induced high-speed flow dynamics
Authors: Znamenskaya I. , Koroteeva E. , Doroshchenko I.
Published: September 2020

Energy deposition from pulsed plasma-based devices is of research interest due to their promising flow control applications. Here, we report on a combined experimental and numerical study of a high-speed flow induced by a column-shaped, pulsed discharge at low pressure. The energy release time is analyzed based on the relative dynamics of the shock and contact fronts. Time-resolved shadow imaging is performed to capture the evolution of two cylindrical flow discontinuities—a shock wave and a contact surface—from 4 µs up to 25 µs after discharge pulse. The comparison of the experimental data with the numerical predictions confirms that the heating of gas by the pulsed plasma occurs within one microsecond after nanosecond discharge initiation.
Ab initio valence bond theory: A brief history, recent developments, and near future
Authors: Chen Zhenhua , Wu Wei
Published: September 2020

This Perspective presents a survey of several issues in ab initio valence bond (VB) theory with a primary focus on recent advances made by the Xiamen VB group, including a brief review of the earlier history of the ab initio VB methods, in-depth discussion of algorithms for nonorthogonal orbital optimization in the VB self-consistent field method and VB methods incorporating dynamic electron correlation, along with a concise overview of VB methods for complex systems and VB models for chemical bonding and reactivity, and an outlook of opportunities and challenges for the near future of the VB theory.
All transparent high-performance solar-blind n-ITO/p-NiO/n-ZnO ultraviolet heterojunction bipolar phototransistor
Authors: Hwang J. D. , Hwang Y. E. , Chen Y. A.
Published: September 2020

All transparent high-performance solar-blind n-ITO/p-NiO/n-ZnO ultraviolet heterojunction bipolar phototransistors (HBPTs) were fabricated using a low-cost radio frequency magnetron sputtering system. In the HBPT structure, ITO, NiO, and ZnO were employed as the emitter, base, and collector, respectively. The applied voltage is across the emitter and collector, and the base is floating. The photocurrent increases with the collector–emitter voltage (VCE). The prepared HBPTs presented the highest optical gain of 7.4 × 104 and a responsivity of 1.67 × 104 A/W, at VCE = 4 V for the 280-nm illumination wavelength. As VCE exceeds 4 V, the optical gain and responsivity decrease owing to the punch-through effect. The prepared HBPTs have an ultraviolet (UV)/visible rejection ratio of more than three orders, allowing their use in practical applications as UV detectors for weak UV signals.
Progress on and challenges of p-type formation for GaN power devices
Authors: Narita Tetsuo , Yoshida Hikaru , Tomita Kazuyoshi , Kataoka Keita , Sakurai Hideki , Horita Masahiro , Bockowski Michal , Ikarashi Nobuyuki , Suda Jun , Kachi Tetsu , Tokuda Yutaka
Published: September 2020

The fabrication processes of p-type regions for vertical GaN power devices are investigated. A p-type body layer in a trench gate metal-oxide-semiconductor field-effect transistor requires precise control of the effective acceptor concentration, which is equal to the difference between the Mg acceptor concentration (Na) and the compensating donor concentration (Nd). The carbon atoms incorporated during growth via metalorganic vapor phase epitaxy substitute nitrogen sites (CN) and function as donor sources in a p-type GaN layer. Since interstitial H atoms (Hi) also compensate holes, their removal from an Mg-doped layer is crucial. Extended anneals to release H atoms cause the formation of extra hole traps. The p+ capping layer allows effective and rapid removal of H atoms from a p-type body layer owing to the electric field across the p+/p– junction. On the other hand, selective area p-type doping via Mg ion implantation is needed to control the electrical field distribution at the device edge. Ultrahigh-pressure annealing (UHPA) under a nitrogen pressure of 1 GPa enables post-implantation annealing up to 1753 K without thermal decomposition. Cathodoluminescence spectra and Hall-effect measurements suggest that the acceptor activation ratio improves dramatically by annealing above 1673 K as compared to annealing at up to 1573 K. High-temperature UHPA also induces Mg atom diffusion. We demonstrate that vacancy diffusion and the introduction of H atoms from the UHPA ambient play a key role in the redistribution of Mg atoms.
Resources for Implementing the NGSS
Authors:   AAPT
Published: September 2020

The following documents from the American Association for the Advancement of Science (AAAS) spearheaded the Project 2061 initiative to improve science literacy for all by providing broad descriptive and unifying themes of natural, mathematical, and social sciences, goals for student achievement, and atlases that displayed the deep interconnectedness of the sciences.
Gravitational Force I
Authors: Camp Charles W. , Clement John J.
Published: September 2020

While many teachers would see direct instruction on Newton’s law of universal gravitation as the way to initiate teaching about gravity, we have discovered that students retain some of the more basic preconceptions listed above in spite of straightforward “correct” instruction. Thus, the first day’s lesson in this section is designed to specifically confront and examine the problems with these widely held preconceptions.
Third Law in Dynamics
Authors: Camp Charles W. , Clement John J.
Published: September 2020

These lessons, like previous lessons in this series, make use of analogies to teach difficult concepts. The instructional strategy is based on anchors introduced in earlier lessons. The unit also employs a variety of other techniques such as student voting, open discussions, collision demonstrations using students, and other laboratory experiments. This variety is built into the lessons to maintain student interest as the teacher carefully works to unpack their interwoven set of preconceptions.
Radiation Hazards
Authors:   American Association of Physics Teachers Apparatus Committee
Published: September 2020

Radioactivity is a process where unstable nuclides seek a more stable nuclear state. This can occur in two ways: by the spontaneous emission (decay) of a high energy particle and a photon or by spontaneous nuclear fission. The former is more common and will be the focus of our discussion.
Magnets and Properties of Magnets
Authors: Nelson Jane Bray , Nelson Jim
Published: September 2020

Materials needed per group:Bar magnetBag labeled “A” with assorted objects
Newton’s Second Law: Activities and Understanding
Authors: Morse Robert A.
Published: September 2020

Newton’s second law organizes the cause and effect relationships of classical mechanics. Understanding the second law is essential to understanding the Newtonian model of how the world works—a model that describes the behavior of common objects at common scales and speeds, and supplies the vocabulary for understanding the more advanced models of modern physics. A serious understanding of the second law is not only essential for a theoretical understanding of Newtonian mechanics, but also has practical applications. Understanding the second law can save your life on the highway.
Acknowledgments
Authors: Morse Robert A.
Published: September 2020

First and most importantly, I thank my collaborators on the 1993 version of this manual, Priscilla Laws, David Sokoloff, Ronald Thornton, and especially Maxine Willis, who was the lead author of that version. This manual draws heavily on their work and incorporates many ideas developed both independently and collaboratively by all of us.
Getting Started: Possible First Day Activities
Authors: Mader Jan , Winn Mary
Published: September 2020

The study of physics using the learning cycle approach can begin on the first day of school with any of the activities in Getting Started. The laboratory activity Dancing Raisins is a complete learning cycle, introducing the students to the science process skills of experimental design, variable control, observation, data collection, inference, prediction, and analysis.
Analysis of Data
Authors: Mader Jan , Winn Mary
Published: September 2020

How can a student determine the relationship that exists between variables of an experiment? Or more importantly, how can a student explain her findings to another person once that data has been collected? The study of physics involves the design of experiments, the collection of data, and ultimately the analysis of that data to determine the relationship between the variables in the experiment.
Kinematics: Motion in One Dimension
Authors: Mader Jan , Winn Mary
Published: September 2020

Kinematics, the study of motion, is typically the first area of physics content addressed in most high school curricula. The following are some common misconceptions students may have with respect to kinematics: Velocity is the same concept as speed.Two objects at the same position have the same velocity.Velocity and acceleration mean the same thing.An object’s mass determines its acceleration in free fall. A more massive object accelerates faster than a less massive object.Acceleration and velocity are always in the same direction and an object with no velocity can have no acceleration.
Motion in Two Dimensions and Vectors
Authors: Mader Jan , Winn Mary
Published: September 2020

The topic of vectors is basic to understanding the concepts of classical mechanics, and yet what may appear simple to the instructor causes frustration and confusion on the part of the student. The terms “distance” and “displacement” or “speed” and “velocity” are used interchangeably in common language.
Universal Gravitation
Authors: Mader Jan , Winn Mary
Published: September 2020

Of the four fundamental forces in nature, gravity is the most familiar and far reaching. To the early Greeks, objects fell because they were seeking their natural place, earth. Newton is credited with the idea of gravity, although Copernicus alluded to the concept of gravity in his theory of the heliocentric universe. The concept of weight and gravity is fundamental to the understanding of centripetal force and objects in orbit.
Data Analysis
Authors: Lehman Cherie Bibo , Antinone Linda J. , Gastineau John E.
Published: September 2020

A straightforward method for determining the acceleration due to gravity is to collect position and time data for a freely falling object. Side A, chapter 43 of the Physics Cinema Classics videodisc contains a video clip of a falling bowling ball, which was filmed at 18 frames per second. A four-meter path enables the student to determine the scale factor used in the clip. Students can mark the position of the ball on the screen as they advance the sequence one frame at a time. The frame number can be displayed on the screen so students can keep track of the number of frames from which measurements are made. The time interval between successive frames is 1/18 second.
Weighing the Universe, and Dark Matter
Authors: Krauss Lawrence M. , Starkman Glenn D.
Published: September 2020

When discussing the expansion of the universe in Chapter 2, we described how important it is to determine the total matter content if we are to be able to determine the eventual fate of our expanding universe. We alluded there to the necessity of “weighing the universe.” Here we describe how this process is accomplished, via various activities. When this process is carried out to weigh our galaxy and nearby clusters of galaxies, it is found that the mass contained therein is far larger than can be accounted for by visible material. This “dark matter” therefore plays an essential role in the dynamics of the universe on large scales. Determining the nature of the dark matter is presently one of the major research programs in cosmology. We will describe, via two exercises, different aspects of this search for dark matter.
Clustering and Large Scale Structure Formation
Authors: Krauss Lawrence M. , Starkman Glenn D.
Published: September 2020

One of the outstanding unsolved problems in cosmology is exactly how all the structure in the universe formed. As we shall discuss in greater detail in the next section, when we use the cosmic microwave background to look on the largest scales the universe is characterized by its remarkable homogeneity — the density averaged over a volume of a few billion parsecs cubed is apparently smooth to one part in 100,000. On the other hand, on smaller scales the universe is progressively more and more lumpy with stars making up galaxies grouped into clusters of galaxies and superclusters of galaxies. How does one progress from a state that is so smooth to one that is so clumped?
Introduction
Authors: Franklin Bill
Published: September 2020

The title of this manual contains its central message: that impulse should be uttered in the same breath with momentum. There are many situations in which momentum is conserved (or nearly so), and impulse need not be explicitly invoked to get a useful solution using momentum. But there are many more situations in which momentum changes, and solutions can be found only by considering impulse. Even when momentum is conserved, you can only know that by convincing yourself that the net impulse on the system in question is zero. The proper approach, then, is always to examine impulse first.
Physics Olympics or Contests
Authors: Franklin Bill
Published: September 2020

This section has a few ideas that can be used for a Physics Olympics or just a classroom competition. In general, the more involved you get students in using concepts, the better they learn them. Contests often help.
Modern Physics Applications
Authors: Franklin Bill
Published: September 2020

There is much in modern (20th century) physics that cannot be explained by classical physics, but also much that can. Even when classical physics is inadequate, the classical quantities of momentum and energy are still an essential part of our understanding.
Assessment Questions
Authors: Franklin Bill
Published: September 2020

The test questions listed here are from a bank developed over the 1968–1995 period with the help of Mike Saathoff and Julia Cox, colleagues in the Spring Branch School District in Houston, Texas. Mike translated my original mainframe BASIC program of 1968 to the Apple IIe in 1985, and subsequently greatly improved it, especially by including graphics capability in both questions and choices.
Teaching High School Physics
Authors: Wenning Carl J. , Vieyra Rebecca E.
Published: September 2020

Teaching High School Physics is centered on the principle that teachers need to be educated rather than trained and helps to form a substantive and substantiated foundation for a new way of teaching. Providing a mix of theory and practice, these books describe more than 40 important topics and encourage an inquiry-oriented approach to physics teaching. They include numerous examples and helpful resources.

The Nature of Physics Teaching:Explores the role of educational research, teaching philosophies, and scientific epistemology as a foundation for good teachingPlaces a strong emphasis on learning by inquiryPrepares teachers with a solid philosophical and practical foundation focusing on the nature of physics teaching

Teaching High School Physics is suitable for teacher candidates, experienced in-service physics teachers, and educators seeking a detailed reference guide to the many subjects being addressed in today's teaching reform movements.
Scientific Inquiry in Introductory Physics
Authors: Wenning Carl J. , Vieyra Rebecca E.
Published: September 2020

Physics teachers must have a thorough understanding of scientific inquiry so that they come to value it, are more likely to practice it properly, and understand how to help students achieve a higher degree of scientific literacy. Teachers and students often resist the use of scientific inquiry because it can require more time and effort. However, the explicit incorporation of scientific inquiry helps to demonstrate authentic practices of scientists and the historical advancement of scientific knowledge.
Mathematical Methods of Inquiry
Authors: Wenning Carl J. , Vieyra Rebecca E.
Published: September 2020

The ability to mathematical represent relationships and to quantify error is an essential skill for physics students. Students are sometimes asked to determine how well overall experimental results align with a theoretical expectation. Teachers should be familiar with dimensional analysis to help students develop theoretical models for relationships and error propagation. This chapter describes the simple pendulum lab and uses it uses it as an exemplar for understanding the methods of scientific inquiry.
Teaching High School Physics
Authors: Wenning Carl J. , Vieyra Rebecca E.
Published: September 2020

Teaching High School Physics is centered on the principle that teachers need to be educated rather than trained and helps to form a substantive and substantiated foundation for a new way of teaching. Providing a mix of theory and practice, these books describe more than 40 important topics and encourage an inquiry-oriented approach to physics teaching. They include numerous examples and helpful resources.

Interacting with Physics Students:Addresses practical techniques for supporting student learning in the day-to-day classroomDetails how to facilitate active engagement and cooperation in an equitable manner, manage learning difficulties and diferentiations, and other situations teachers face in the classroomPrepares teachers with a solid philosophical and practical foundation focusing on interactions with students

Teaching High School Physics is suitable for teacher candidates, experienced in-service physics teachers, and educators seeking a detailed reference guide to the many subjects being addressed in today's teaching reform movements.
Active and Engaged Learning
Authors: Wenning Carl J. , Vieyra Rebecca E.
Published: September 2020

Students learn best when they are both active (“hands-on”) and engaged (“minds-on”). Accomplishing this task requires that teachers keep students motivated and interested in the lesson at hand. Active and engaged learning are both entirely compatible with, and often are an inherent part of, particular teaching strategies (such as inquiry, cooperative, and real-world learning). However, this topic deserves its own presentation because there are times when students lose momentum throughout a class period or over a year, and teachers must continue to pique students’ interest using a variety of specific interventions. This chapter describes the general principles behind active and engaged learning, and provides a potpourri of ideas to excite student interest and incorporate a bit of fun!
Alternative Conceptions
Authors: Wenning Carl J. , Vieyra Rebecca E.
Published: September 2020

Science teachers know that students enter the classroom with many alternative conceptions—notions that are naive, incomplete, or sometimes contrary to those generally accepted by mainstream scientists. Some alternative conceptions can be doggedly resistant to change, making it difficult for students and teachers to improve conceptual understanding. Other alternative conceptions seem to be used inconsistently by students, making it difficult for students and teachers to identify the flaws in their thinking. We propose two emphases within the context of a “classical model” for more effectively overcoming alternative conceptions based on the results of cognitive research.
Student Difficulties in Problem-Solving
Authors: Wenning Carl J. , Vieyra Rebecca E.
Published: September 2020

Why do intelligent, knowledgeable, dedicated, and motivated students working under the best of conditions sometimes struggle to learn various aspects of physics? Physics teachers all too frequently find themselves asking, “How is it that these students just don't get it? The concept is so simple!” There is considerably more to the learning to teach physics than instructional methods, alternative conceptions, innate and learned intelligence, motivation, effort, and study skills. This chapter examines attempts to provide insights into this recurrent and vexing problem.
Differentiated Teaching
Authors: Wenning Carl J. , Vieyra Rebecca E.
Published: September 2020

No two students who enter a physics classroom are alike. Getting to know students on an individualized level reveals an wide diversity of backgrounds, experiences, attitudes, interests, preferences, and abilities. Further inquiries and experiences with these students will demonstrate that not all students prefer to learn in the same way, that certain experiences might help one student to understand a concept but have no effect on another, and that the same things do not motivate all students. Furthermore, a single type of assessment might not accurately demonstrate what students with varying skill sets know. Teachers who are aware of and sensitive to differences will encourage all students to be successful by “meeting them where they are” through differentiated curriculum, instruction, and assessment.
Cultural, Linguistic, and Gender Diversity
Authors: Wenning Carl J. , Vieyra Rebecca E.
Published: September 2020

No two students are alike, and although differentiation can individually address the learning needs of many students, for others, equity cannot be achieved until teachers make holistic changes in the classroom. Students sometimes need assistance, encouragement, and invitation to take part in the learning process—namely, those of varying backgrounds influenced by gender, socioeconomic status, orientation, religion, race, dominant language, or culture. Teachers must work proactively to avoid teacher, student, or institutional bias and to ensure that all students receive fair opportunity and support in the educational process.
Social and Emotional Learning
Authors: Wenning Carl J. , Vieyra Rebecca E.
Published: September 2020

It is incumbent upon teachers to educate the whole student—academically, socially, and emotionally—if we are to expect students to benefit maximally from their limited time with us. Building relationships with and among students is key to holistic development. Research by the American Psychological Association suggests that student achievement in school is strongly dependent upon positive teacher-student relationships, and science itself is a communal endeavor, requiring students to build positive student-student relationships. The crux of social and emotional learning is to help students to improve their resilience as learners and to become well integrated, contributing members of society.
Legal, Safe, and Ethical Teaching
Authors: Wenning Carl J. , Vieyra Rebecca E.
Published: September 2020

Teachers bear a heavy responsibility to help students to develop intellectually, socially, and emotionally, while at the same time providing for their physical and emotional safety. As a result, all teachers should be aware of the legalities associated with their profession, including rights and limitations. Safety stands at the forefront of teacher responsibilities, especially with respect to student work in laboratory or field settings that pose an increased amount of risk. Lastly, teachers must have a well-founded set of ethical standards to guide their professional conduct in and out of the classroom.
Unit Planning
Authors: Wenning Carl J. , Vieyra Rebecca E.
Published: September 2020

Following the development of a curriculum, the next logical step in teaching is unit planning. Unit plans are integral to the instructional process because their development requires a teacher not only to carefully consider course content in detail, but also to think about and synthesize all that he or she knows about teaching, students, and standards. A well-prepared unit plan will include learning objectives, a timeline, learning sequences, implementation ideas, resources, and formative and summative assessments. Unit planning is the best time to align student performance objectives, assessments, and major learning activities.