Characterisation of nickel germanide formed on amorphous and crystalline germanium

Germanium offers unique properties as a semiconductor materials for complementary metal–oxide–semiconductor (CMOS) devices with nearly four times the hole mobility and two times the electron mobility of silicon resulting in higher currents. However, two essential requirements in the application of Ge for CMOS technology are the formation of shallow junctions and the formation of ohmic metal contacts with low resistance. High diffusivity of dopants in crystalline germanium is a problem when forming shallow junctions. However, amorphisation of crystalline germanium where dopant implants are to occur leads to shallow junctions. In this work both amorphous and crystalline germanium (a-Ge and c-Ge) are investigated. Nickel germanide (NiGe) formed on a-Ge and c-Ge is investigated for material and electrical properties. NiGe has been reported as a suitable germanide for low resistance ohmic contacts on c-Ge. The crystal quality of films formed is poorer for the germanides formed on a-Ge but there is only a slight increase in sheet resistance. The grains of NiGe formed on a-Ge show a growth that is hexagonal like, extending into the substrate further than germanides grains formed on crystalline germanium. The NiGe formed on c-Ge has a much more uniform thickness and uniform grain size and shape. Thin films of nickel germanide conveniently form at the relatively low temperature of 300C in a matter of minutes and at even lower temperatures over a longer time. This thesis reports on the formation of NiGe on c-Ge substrates at low temperatures (less than 300°C). Ni films deposited on Ge substrates formed NiGe by heating the samples in an atmosphere VI nearly void of oxygen. Ni films of thickness 50 to 400 nm were deposited on c-Ge and heat treatments undertaken on samples for time durations of 5 minutes to 12 hours at different temperatures. It was found that thickness of 25nm to 100 nm was not a significant factor and that NiGe formed in a few minutes on c-Ge for this thickness of Ni heated at 300°C. The temperature of formation for 400 nm reacting with germanium was longer. For all thickness of Ni, long durations were required for the lowest temperature of formation which were between 225°C and less than 300°C. The sheet resistances of NiGe on a-Ge and c-Ge are suitably low for use in CMOS technology. Metal contacts to NiGe were investigated and low resistance contacst were obtained. The contacts to c-Ge were significantly better. Improvements in processing is required for suitably low resistance contacts to be obtained for metal to NiGe formed on aGe, but results obtained here are promising and further investigation is warranted. NiGe on a-Ge shows poorer grain crystal quality and improvements in this are likely to lead to contacts with lower specific contact resistivity

The Role of Translation in Language Change: A Corpus-based Study on English Influence on the Arabic Passive

Studies conducted around the world have shown that the structures of various languages have shifted over time towards that of English. This phenomenon could be attributed to the use of English as a lingua franca or to these languages’ contact with English via translation. This thesis investigates this shift towards English-language structure in translated and original Arabic scientific texts. To this end, I developed a diachronic corpus for scientific articles dating between 1997-2000 and 2016-2018 to generate findings for this genre. The study used both parallel and comparable corpora, allowing an investigation of the influence of English not only on translated texts but also on original scientific texts written within the same time frame. The results reveal that the English language has affected the Arabic passive voice structure in translated scientific texts, and that the English passive voice structure seems also to have affected original modern Arabic scientific texts. As for the agentive passive, English does not seem to have increased its influence between 1997-2000 and 2016-18 in the translated texts as most agentive English passives are translated into active Arabic sentences in both the 1997- 2000 and 2016-18 corpora. There also does not seem to be a significant increase in the agentive passive in original texts between 1997-2000 and 2016-2018

New insight into strategies used to develop long-acting G-CSF biologics for neutropenia therapy

Over the last 20 years, granulocyte colony-stimulating factors (G-CSFs) have become the major therapeutic option for the treatment of patients with neutropenia. Most of the current G-CSFs require daily injections, which are inconvenient and expensive for patients. Increased understanding of G-CSFs’ structure, expression, and mechanism of clearance has been very instrumental in the development of new generations of long-acting G-CSFs with improved efficacy. Several approaches to reducing G-CSF clearance via conjugation techniques have been investigated. PEGylation, glycosylation, polysialylation, or conjugation with immunoglobulins or albumins have successfully increased G-CSFs’ half-lives. Pegfilgrastim (Neulasta) has been successfully approved and marketed for the treatment of patients with neutropenia. The rapidly expanding market for G-CSFs has increased demand for G-CSF biosimilars. Therefore, the importance of this review is to highlight the principle, elimination’s route, half-life, clearance, safety, benefits, and limitations of different strategies and techniques used to increase the half-life of biotherapeutic G-CSFs. Understanding these strategies will allow for a new treatment with more competitive manufacturing and lower unit costs compared with that of Neulasta

Recent Updates of the CRISPR/Cas9 Genome Editing System: Novel Approaches to Regulate Its Spatiotemporal Control by Genetic and Physicochemical Strategies

Khaled S Allemailem,1 Ahmad Almatroudi,1 Arshad Husain Rahmani,1 Faris Alrumaihi,1 Arwa Essa Alradhi,2 Amal M Alsubaiyel,3 Mohammad Algahtani,4 Rand Mohammad Almousa,5 Ali Mahzari,6 Abdulmajeed AA Sindi,7 Gasim Dobie,8 Amjad Ali Khan9 1Department of Medical Laboratories, College of Applied Medical Sciences, Qassim University, Buraydah 51452, Saudi Arabia; 2General Administration for Infectious Disease Control, Ministry of Health, Riyadh 12382, Saudi Arabia; 3Department of Pharmaceutics, College of Pharmacy, Qassim University, Buraydah 51452, Saudi Arabia; 4Department of Laboratory & Blood Bank, Security Forces Hospital, Mecca 21955, Saudi Arabia; 5Department of Education, General Directorate of Education, Qassim 52361, Saudi Arabia; 6Department of Laboratory Medicine, Faculty of Applied Medical Sciences, Al-Baha University, Al-Baha 65527, Saudi Arabia; 7Department of Basic Medical Sciences, Faculty of Applied Medical Sciences, Al-Baha University, Al-Baha 65527, Saudi Arabia; 8Department of Medical Laboratory Technology, Faculty of Applied Medical Sciences, Jazan University, Gizan 82911, Saudi Arabia; 9Department of Basic Health Sciences, College of Applied Medical Sciences, Qassim University, Buraydah 51452, Saudi ArabiaCorrespondence: Amjad Ali Khan, Department of Basic Health Sciences, College of Applied Medical Sciences, Qassim University, P.O. Box 6666, Buraydah, 51452, Saudi Arabia, Email [email protected]: The genome editing approach by clustered regularly interspaced short palindromic repeats (CRISPR)/associated protein 9 (CRISPR/Cas9) is a revolutionary advancement in genetic engineering. Owing to its simple design and powerful genome-editing capability, it offers a promising strategy for the treatment of different infectious, metabolic, and genetic diseases. The crystal structure of Streptococcus pyogenes Cas9 (SpCas9) in complex with sgRNA and its target DNA at 2.5 Å resolution reveals a groove accommodating sgRNA:DNA heteroduplex within a bilobate architecture with target recognition (REC) and nuclease (NUC) domains. The presence of a PAM is significantly required for target recognition, R-loop formation, and strand scission. Recently, the spatiotemporal control of CRISPR/Cas9 genome editing has been considerably improved by genetic, chemical, and physical regulatory strategies. The use of genetic modifiers anti-CRISPR proteins, cell-specific promoters, and histone acetyl transferases has uplifted the application of CRISPR/Cas9 as a future-generation genome editing tool. In addition, interventions by chemical control, small-molecule activators, oligonucleotide conjugates and bioresponsive delivery carriers have improved its application in other areas of biological fields. Furthermore, the intermediation of physical control by using heat-, light-, magnetism-, and ultrasound-responsive elements attached to this molecular tool has revolutionized genome editing further. These strategies significantly reduce CRISPR/Cas9’s undesirable off-target effects. However, other undesirable effects still offer some challenges for comprehensive clinical translation using this genome-editing approach. In this review, we summarize recent advances in CRISPR/Cas9 structure, mechanistic action, and the role of small-molecule activators, inhibitors, promoters, and physical approaches. Finally, off-target measurement approaches, challenges, future prospects, and clinical applications are discussed.Keywords: CRISPR/Cas9, sgRNA, genome editing, off-target effects, spatiotemporal control, clinical translatio

Investigating resistance of layers in nickel germanide formed on amorphous and crystalline germanium

Nickel germanide formed on amorphous and crystalline germanium was investigated for sheet resistance, resistivity and specific contact resistivity of A1 to the NiGe layers. This paper reports on electrical characterization of NiGe using both c-Ge and a-Ge

Investigation on the Factors Associated with the Persistence of Anosmia and Ageusia in Saudi COVID-19 Patients

The Coronavirus Disease 2019 (COVID-19) outbreak caused by the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) resulted in a worldwide pandemic of a highly infectious disease. The difficulty of dealing with COVID-19 is the broad spectrum of clinical manifestations that involves various pathophysiological mechanisms, severities, duration, and complications. This study aims to help emphasize the factors related to the persistence and duration of anosmia (loss of smell) and ageusia (loss of taste) as part of post-acute COVID-19 syndrome in Saudi COVID-19 patients via a retrospective cross-sectional design. Eight hundred and eighty-one participants were recruited between March and April 2021. Those participants were 18 years or older, recovered from the COVID-19 infection, and completed 14 days after the onset of the acute phase of the disease. Among the 881 recruited participants, 808 have submitted eligible responses and were included in data analyses. The most common persistent symptoms in post-acute COVID-19 syndrome were anosmia (33.8%) and ageusia (26.4%). The data also showed a significant association between female sex and the incidence and the persistence of anosmia and ageusia. In multivariable analysis, anosmia during the acute phase was associated with BMI, asthma and shortness of breath, while anosmia during the post-acute phase was associated with sex. Ageusia during the acute phase was associated with sex, myalgia and arthralgia, while ageusia in the post-acute phase was associated with sex

Cyclic fatigue resistance of EdgeTaper Platinum, Protaper Gold, and TruNatomy Prime rotary files before and after autoclave sterilization

Background This in vitro investigation aimed to determine the influence of multiple autoclave cycles on the cyclic fatigue resistance of three heat-treated nickel-titanium (NiTi) files: EdgeTaper Platinum (ETP), ProTaper Gold (PTG), and TruNatomy Prime (TN). Materials Sixty NiTi files, twenty of each NiTi file type: ETP 25/.06, PTG 25/.08, and TN 26/.04 were randomly divided into four equal subgroups (n = 5). The files for the control group were left un-autoclaved. Different autoclave sterilization cycles (one, five, and ten) were used for the other three groups. The files were then placed in a metal canal block and rotated according to the manufacturer’s instructions until fracture. The length of the broken segment and the time taken for fracture were measured. The fractured surfaces were subsequently subjected to SEM imaging. The Kruskal-Wallis test was used to analyze the data, followed by Dunn-Bonferroni pairwise comparisons. Statistical significance was set at p < 0.05. Results ETP showed significantly greater resistance to cyclic fatigue than TN in all autoclave groups and PTG after five autoclave cycles (p = 0.014). Fatigue resistance was not affected by the number of autoclaving cycles, except for ETP. After the first and tenth autoclaving cycles, they required significantly more rotations to failure than the non-sterilized files (p = 0.039 and p = 0.021, respectively). The fractured segments of the ETP files in these two groups were also longer than those in the control group (p = 0.010). Conclusion The cyclic fatigue resistance of ETP was greater than that of TN in all tested conditions. Repeated autoclave cycles of sterilization improved the cyclic fatigue resistance of the ETP files only and did not affect the cyclic fatigue resistance of TN and PTG. However, the ETP files separated at a longer distance from the tip with increased autoclaving cycles

Low temperature of formation of nickel germanide on crystalline germanium

Thin films of nickel germanide conveniently form at the relatively low temperature of 300C in a matter of minutes and at even lower temperatures over a longer time. Here we report on the formation of NiGe on crystalline germanium substrates at low temperatures (less than 300C). Ni films deposited on Ge substrates formed NiGe by heating the samples in an atmosphere nearly void of oxygen. Ni films of thickness 50 to 400nm were deposited on crystalline germanium and heat treatments undertaken on samples for time durations at different temperatures of 5 minutes to 12 hours. It was found that the thickness was not a significant factor and that NiGe formed in a few minutes for all thicknesses heated at 300 C. Long durations were required for the lowest temperature of formatio