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Germanium–tin (GeSn) alloys at sufficiently high Sn concentration, above several atomic percent, are the only group IV semiconductor exhibiting a direct bandgap and have generated much recent interest for optoelectronic applications into the mid-infrared region. Because the large lattice mismatch between GeSn and Si results in considerable strain for thin layers and a high defect density for thicker strain-relaxed layers, most reported GeSn growths incorporate a Ge buffer layer rather than depositing directly on Si substrates. Published reports of GeSn growth directly on Si utilize specialized precursors such as higher order germanes (Ge2H6, Ge3H8, or Ge4H10) or SnD4. In this paper, we report GeSn films with up to 10.6% Sn grown directly on Si substrates by remote plasma-enhanced chemical vapor deposition using GeH4 and SnCl4 precursors. These alloys have been characterized in detail using x-ray diffraction (XRD), transmission electron microscopy (TEM), and Rutherford backscattering spectrometry with channeling (RBS-C), as well as Raman spectroscopy (RS) and optical microscopy. The films studied are almost fully relaxed, with small residual strain observed, particularly in thinner films, and contain a high interface density of misfit dislocations that increases with Sn concentration. The defect density decreases toward the surface. Good agreement is found between the various characterization methods for the Sn content (XRD and RBS-C), lattice parameter measurement (XRD and TEM), and defect characterization (RBS-C, TEM, and RS). Such characterization of GeSn grown directly on Si substrates is essential to allow growth parameters to be optimized for the realization of the attractive optoelectronic properties of these alloys. [ABSTRACT FROM AUTHOR]

GeSn films were simultaneously deposited on Si (100), Si (111), c-plane sapphire (Al2O3), and fused silica substrates to investigate the impact of the substrate on the resulting GeSn film. The electronic, structural, and optical properties of these films were characterized by temperature-dependent Hall-effect measurements, x-ray diffractometry, secondary ion mass spectrometry, and variable angle spectroscopic ellipsometry. All films were polycrystalline with varying degrees of texturing. The film on Si (100) contained only GeSn (100) grains, 40.4 nm in diameter. The film deposited on Si (111) contained primarily GeSn (111) grains, 36.4 nm in diameter. Both films deposited on silicon substrates were fully relaxed. The layer deposited on Al2O3 contained primarily GeSn (111) grains, 41.3 nm in diameter. The film deposited on fused silica was not textured, and the average grain size was 35.0 nm. All films contained ∼5.6 at. % Sn throughout the layer, except for the film deposited on Al2O3, which contained 7.5% Sn. The films deposited on Si (111), Al2O3, and fused silica exhibit p-type conduction over the entire temperature range, 10–325 K, while the layer deposited on the Si (100) substrate shows a mixed conduction transition from p-type at low temperature to n-type above 220 K. From ∼175 to 260 K, both holes and electrons contribute to conduction. Texturing of the GeSn film on Si (100) was the only characteristic that set this film apart from the other three films, suggesting that something related to GeSn (100) crystal orientation causes this transition from p- to n-type conduction. [ABSTRACT FROM AUTHOR]

Semiconductors with the general formula Al(As1–xPx)Si3havebeen theoretically studied and synthesized. These new materials aregrown on Si(100) at 490–500 °C as single-phase epitaxiallayers with monocrystalline diamond-like structures using reactionsof Al atomic beams with As(SiH3)3and P(SiH3)3molecular sources. An intriguing outcome ofthe reaction behavior is that there appears to be no preference inthe interaction between Al and the As(SiH3)3and P(SiH3)3coreactants, leading to the organizedassembly of the corresponding Al–As–Si3andAl–P–Si3building blocks into a tetrahedrallattice in which the P/As atoms are arranged in a common third nearestneighbor sublattice in a manner that precludes the formation of energeticallyunfavorable Al–Al bonds. The translation of these molecularbuilding blocks into the crystalline structures is elucidated usingquantum chemistry. A general crystallographic description for theprimitive cell is introduced and used to carry out first principlecalculations of the structural, thermodynamic and electronic propertiesof AlP1–xAsxSi3. The results indicate that these materials areindirect gap semiconductors with indirect gaps similar to that ofSi but with smaller direct gaps, which should increase their absorptioncoefficients. Raman spectroscopy provides a qualitative confirmationof these predictions as well as important clues on the orientationalorder of the tetrahedral building blocks that make up these novelmaterials. In the context of device design, strain analysis of Al(As1–xPx)Si3indicates that the films are tetragonally compressed dueto an inherent 0.8% (or less) lattice mismatch with the Si substrate.At the highest mismatch of 1.6%, strain relaxation is observed forthicknesses exceeding 40 nm, producing prototype layers with bulk-likebehavior. Collectively, the results demonstrate that it may be feasibleto design and prepare a host of similar systems in this general classof semiconductors with potential optoelectronic applications, includingphotovoltaics. [ABSTRACT FROM AUTHOR]

Lattice-matched Ge1-x-ySixSny (x ≤ 0.2, y ≤ 0.05) alloys were deposited defect-free on Ge(001) substrates via low-temperature (330-290 °C) reactions of Ge4H10, Si4H10 and SnD4 hydrides, and used to fabricate pin photodetectors. The growth is carried out under gas-source molecular beam epitaxy conditions in a specially designed single-wafer reactor. Optical responsivity measurements reveal absorption edges between 0.88 eV and 0.98 eV, which are used to determine the compositional dependence of the direct band gap. A study of the I-V characteristics of the diodes shows that the dark current is very weakly correlated with the number of Si-Sn bonds in the alloy. [ABSTRACT FROM AUTHOR]

The new title materials are grown on Si(100) at 490-500 °C as single-phase epitaxial layers with monocrystalline diamond-like structures using reactions of Al atomic beams with As(SiH3)3 and P(SiH3)3. [ABSTRACT FROM AUTHOR]

Film growth and reaction kinetics studies have shown that trigermane (Ge3H8) is a superior Ge source for the epitaxial synthesis of Ge1-ySny/Si(100) alloys using ultra-high vacuum chemical vapor deposition. The Ge3H8/SnD4 combination yields 3-4 times higher growth rates than the traditional Ge2H6/SnD4 approach, with film Sn/Ge ratios reflecting the corresponding gas-phase stoichiometries much more closely. These advances have led to optical quality Ge1-ySny layers with Sn concentrations up to at least 9% and thicknesses approaching 1 μm. These thick films are found to be crucial for the observation of a strong, tunable photoluminescence signal near the threshold of the predicted direct-indirect bandgap crossover. [ABSTRACT FROM AUTHOR]

Ab initio theoretical simulations of Al(As1-xNx)Si3 alloys, a new class of optoelectronic materials, confirm that these compounds are likely to be disordered via a mechanism that preserves the integrity of the constituent III-V-Si3 tetrahedra but randomizes their orientation in the average diamond lattice of the compound. This type of disorder is consistent with experimental structural data and with the proposed growth mechanism for such alloys, according to which "III: V(SiH3)3" intermediate complexes are formed in the gas phase from reactions between group-III atomic beams and V(SiH3)3 molecules, delivering the entire III-V-Si3 tetrahedra to the growing film. Experimental optical studies of these Al(As1-xNx)Si3 alloys as well as more general [Al(As1-xNx)]ySi5-2y compounds grown on Si substrates were carried out using spectroscopic ellipsometry. The resulting dielectric functions are found to be similar to broadened versions of their counterparts in pure Si. This broadening may have important practical applications, particularly in photovoltaics, because it dramatically enhances the optical absorption of Si in the visible range of the electromagnetic spectrum. A critical point analysis reveals the existence of direct optical transitions at energies as low as 2.5 eV, well below the lowest direct absorption edge of Si at 3.3 eV. Such transitions are predicted theoretically for perfectly ordered III-V-Si3 compounds, and the experimental results suggest that they are robust against tetrahedra onentational disorder. [ABSTRACT FROM AUTHOR]

Background: This study assesses the feasibility of real-time surgical navigation to plan and guide sequential steps during mandible reconstruction on a series of cadaveric specimens., Methods: An image-guided surgical (IGS) system was designed including customized mandible and fibula fixation devices with navigation reference frames and an accompanied image-guided software. The mandibular and fibular segmental osteotomies were performed using the IGS in all five cadaveric patients. Procedural time and cephalometric measurements were recorded., Results: Five real-time IGS mandibulectomy and fibular reconstruction were successfully performed. The mean Dice score and Hausdorff-95 distance between the planned and actual mandible reconstructions was 0.8 ± 0.08 and 7.29 ± 4.81 mm, respectively. Intercoronoid width, interangle width, and mandible projection differences were 1.15 ± 1.17 mm, 0.9 ± 0.56 mm, and 1.47 ± 1.62 mm, respectively., Conclusion: This study presents the first demonstration of a comprehensive image-guided workflow for mandibulectomy and fibular flap reconstruction on cadaveric specimens and resulted in adequate cephalometric accuracy., (© 2024 The Author(s). Head & Neck published by Wiley Periodicals LLC.)

Background: The relationships between 25-hydroxyvitamin D [25(OH)D] and calcium and age-related macular degeneration (AMD) are unclear., Objectives: This study aimed to investigate the causal role of 25(OH)D concentrations, calcium concentrations, and dietary supplements use of vitamin D and calcium on risk of AMD and its subtypes., Methods: Independent genetic variants associated with 25(OH)D and calcium concentrations were used as instrumental variables in published genome-wide association studies (GWASs) of European ancestry. The bidirectional 2-sample Mendelian randomization (MR) analyses were performed using summary-level data from the UK Biobank and FinnGen datasets. Sensitivity analyses were conducted to ensure the robustness of the MR results. The meta-analyses were conducted using both fixed-effect and random-effect models to provide comprehensive and reliable estimates., Results: A standard deviation increase in calcium concentrations was linked to a 14%, 17%, and 13% reduction in the likelihood of developing AMD (95% confidence interval [CI]: 0.77, 0.97), wet AMD (95% CI: 0.73, 0.95), and dry AMD (95% CI: 0.75, 1.00), respectively. No significant causal relationships were detected between genetically predicted 25(OH)D concentrations and AMD and its subtypes (all P > 0.05). The combined analyses showed that higher calcium concentrations were associated with a reduced risk of overall AMD, with an odds ratio of 0.89 (95% CI: 0.81, 0.98)., Conclusions: This study provides evidence supporting the causal relationship between calcium concentrations and risk of AMD and its subtypes, which may have important implications for the prevention, monitoring, and treatment of AMD., (Copyright © 2024 American Society for Nutrition. Published by Elsevier Inc. All rights reserved.)

Background: Developmental dysplasia of the hip (DDH) is a common condition affecting 5 in 1000 newborns. The standard first line of treatment is the use of an orthotic, which has generally high success rates, but can pose substantial difficulties and put undue burden on caregivers. The general experience of caregivers using these orthotics has not been well documented on an orthotic-specific basis. The purpose of this study was to investigate caregiver experience using prescribed DDH orthotics to identify challenges, differences between treatment options, and areas of improvement., Methods: A survey assessing treatment prescription, respondent demographics, and caregiver experience was distributed online to caregivers whose child/children were treated for DDH with an orthotic. Seven-point positively phrased Likert scale statements and open-ended questions were included to assess caregiver experience. The results were analyzed using summary statistics and orthotics with more than 30 responses were selected for more in-depth analysis., Results: A total of 530 survey responses were collected with 63% (334/530) of respondents using a Pavlik harness, 45% (236/530) a Rhino brace, and 13% (67/530) a Denis Browne Bar. The overall weighted average score across all Likert Scale statements was positive for the Pavlik harness, Rhino brace, and Denis Browne Bar at 4.19 (95% CI, 3.83 to 4.54), 4.63 (95% CI, 4.27 to 4.99) and 4.91 (95% CI, 4.58 to 5.24), respectively. In the open-ended responses, all 3 orthotics were perceived as easy to use and not hindering child-caregiver bonding, but raised concerns of discomfort and skin irritation, as well as preventing the ability to cuddle their child the way they desired. The Pavlik harness respondents consistently brought up concerns regarding cleanability., Conclusions: The results show that the DDH orthotics analyzed are generally easy to use and perceived positively by caregivers, but have orthotic-specific challenges that should be a focus of future improvement work., Clinical Relevance: This study evaluated opinions and attitudes of caregivers for children being treated with DDH orthotics, revealing experiences, concerns, and challenges associated with the use of commonly prescribed options., Competing Interests: K.M. receives funding support from the I’m a HIPpy Foundation, the Peterson Fund for Global Hip Health, IHDI, BC Children’s Hospital Foundation, the Canadian Orthopaedic Foundation, POSNA, Divi’s Foundation for Gifted Children, Johnson & Johnson, Pega Medical and OrthoPediatrics. The remaining authors declare no conflicts of interest., (Copyright © 2022 The Author(s). Published by Wolters Kluwer Health, Inc.)

Here, we investigate the use of few-layer metal organic chemical vapor deposition (MOCVD) grown BN as a two-dimensional buffer layer for plasma enhanced atomic layer deposition (PE-ALD) of Al 2 O 3 on graphene for top gated field effect transistors (FETs). The reactive nature of PE-ALD enables deposition of thin (2 nm) dielectrics directly on graphene and other two-dimensional materials without the need for a seed or functionalization layer; however, this also leads to significant oxidation of the graphene layer as observed by Raman. In FETs, we find this oxidation destroys conductivity in the graphene channel. By transferring thin (1.6 nm) MOCVD BN layers on top of graphene channels prior to PE-ALD, the graphene is protected from oxidation enabling BN/Al 2 O 3 layers as thin as 4 nm. Raman and X-ray photoelectron spectroscopy on BN films show no significant oxidation caused by PE-ALD of Al 2 O 3 . Inserting the BN layer creates an atomically abrupt interface significantly reducing interface charges between the graphene and Al 2 O 3 as compared to use of a 2 nm Al buffer layer. This results in a much smaller Dirac voltage (- 1 V) and hysteresis (0.9 V) when compared to FETs with the Al layer (V Dirac  = - 6.1 V and hysteresis = 2.9 V).

We introduce a synthetic strategy to access functional semiconductors with general formula A(3)XY (A = IV, X-Y = III-V) representing a new class within the long-sought family of group IV/III-V hybrid compounds. The method is based on molecular precursors that combine purposely designed polar/nonpolar bonding at the nanoscale, potentially allowing precise engineering of structural and optical properties, including lattice dimensions and band structure. In this Article, we demonstrate the feasibility of the proposed strategy by growing a new monocrystalline AlPSi(3) phase on Si substrates via tailored interactions of P(SiH(3))(3) and Al atoms using gas source (GS) MBE. In this case, the high affinity of Al for the P ligands leads to Si(3)AlP bonding arrangements, which then confer their structure and composition to form the corresponding Si(3)AlP target solid via complete elimination of H(2) at ∼500 °C. First principle simulations at the molecular and solid-state level confirm that the Si(3)AlP building blocks can readily interlink with minimal distortion to produce diamond-like structures in which the P atoms are arranged on a common sublattice as third-nearest neighbors in a manner that excludes the formation of unfavorable Al-Al bonds. High-resolution XRD, XTEM, and RBS indicate that all films grown on Si(100) are tetragonally strained and fully coherent with the substrate and possess near-cubic symmetry. The Raman spectra are consistent with a growth mechanism that proceeds via full incorporation of preformed Si(3)AlP tetrahedra with residual orientational disorder. Collectively, the characterization data show that the structuro-chemical compatibility between the epilayer and substrate leads to flawless integration, as expected for pseudohomoepitaxy of an Si-like material grown on a bulk Si platform.

The aim of the present study was to identify deletion/insertion polymorphism of the bovine prion protein (PRNP) gene within the promoter sequence (23 bp indel), intron 1 (12 bp indel) and the 3' end untranslated region (14 bp indel). The experiment was performed on three groups of animals protected under a genetic resources conservation program: 139 Polish Red (PR) cows, 79 Polish White-backed cows and 50 European bison (Bison bonasus L., 1758). White-backed cattle were characterized by a higher frequency of ins/del heterozygotes and a relatively lower frequency of ins/ins homozygotes within the promoter sequence region (23 bp indel), compared to Polish Red cattle. At the polymorphic locus of intron 1 (12 bp indel) the genetic structure of both cattle populations was similar. Monomorphism, expressed by the occurrence of one genotype variant in each of the analyzed sequence regions, was observed in European bison. Five haplotypes were found in Polish White-backed cows, four haplotypes in Polish Red cows and only one in analyzed group of bison. Differences between the observed and expected number of PRNP haplotypes were recorded in Polish Red cattle.

The aim of the present study was to identify the deletion/insertion polymorphism of the bovine prion protein gene (PRNP) within the promoter sequence (23 bp), intron 1 (12 bp) and 3' untranslated region (14 bp). DNA was isolated from blood of 234 randomly tested Polish Holstein-Friesian cows and from semen of 47 sires used for artificial insemination (AI) in 2004. No statistically significant differences were found in the frequency of genotypes and alleles between cows and breeding bulls in the 3 analysed polymorphic sites within the PRNP gene. Only 3 haplotypes were identified in sires and 4 haplotypes in cows.

The molecular basis of BLAD is the D128G mutation of the gene coding for the CD18 subunit of beta-2 integrin. This mutation is lethal, since homozygous (BL/BL) animals die before they reach sexual maturity. In the 1990s, BLAD was the most widespread genetic disease in HF cattle worldwide. The aim of the present study was to determine the frequency of BLAD carriers among 4645 young breeding bulls in Poland in 1995-2006. The frequency of carriers of the mutated allele showed a clear decreasing trend. The highest frequency (7.9%) was recorded while implementing the BLAD control program (1995-1997). Regular monitoring has enabled a great reduction of this threat to the tested population. Today only sporadic cases of BL/TL heterozygotes are reported (ca. 0.8% in 2004-2006).

The hypereosinophilic syndrome is a multi-organ disease characterized by large counts of eosinophils in peripheral blood observed during at least six months without any evidence for other known causes of eosinophilia. Idiopathic hypereosinophilia is rare and is always diagnosed by exclusion of other disease. This work describes a man aged 21 years who was hospitalized at the Department of Dermatology because of skin manifestations resembling eczema and urticaria. High eosinophil counts in this patient necessitated a wide array of diagnostic tests. The hypereosinophilic syndrome was diagnosed after more than 12 months of follow-up and exclusion of other causes. Corticosteroids and hydroxycarbamide were administered as first-line therapy. Unfortunately, the patient was unresponsive to steroids. Improvement in peripheral eosinophilia after Glivec therapy correlated with improved clinical status.

Necrotizing fascitis (NF) is a rare disease with a mortality rate ranging from 24 to 60 percent. The infection may be mono- or polymicrobial and is characterized by extensive necrosis of the skin and muscle, as well as fascia and subcutaneous tissue. NF may develop at the site of injury, e.g. trauma, needle puncture, or surgical incision. The lower extremities, perineum, and abdominal wall are common sites of NF. The remaining 10 percent of cases occur in the upper extremities or neck, usually in patients with vascular disease or diabetes mellitus. The course is rapidly progressive and may be life-threatening if the diagnosis is not made promptly and appropriate surgical debridement is not carried out. We report on a 44-year-old man with necrotizing fascitis during interferon-alpha treatment for hepatitis C virus infection.

DUMPS (Deficiency of Uridine Monophosphate Synthase) is a hereditary recessive disorder in Holstein cattle causing early embryo mortality during its implantation in the uterus. The only way to avoid the economic losses is early detection of DUMPS carriers. Because American Holstein semen has been intensively imported to Poland since 1970, there was a risk that DUMPS could have spread in Polish dairy cattle. In our study, 2209 dairy cattle of the Polish Holstein breed have been screened by the DNA test. The dominant group was young bulls entering the testing program (1171) and proven bulls (781). They represented all sires entering Polish breeding programs between 1999 and 2003. Also, 257 sire dams were included in the screening program. No DUMPS carrier has been found. Our results then indicate that the population of dairy cattle reared in Poland is free from DUMPS. Because of the economical significance of the DUMPS mutation and its recessive mode of inheritance, attention has to be paid to any case of a bull having in his origin any known DUMPS carrier. Such a bull should be tested and if positive eliminated from the active population. Also, young bulls (testing bulls) should be screened for DUMPS if in their progeny a high incidence of embryo mortality is observed and their genealogy cannot exclude their relatedness to any DUMPS carriers.

The aim of our study was to estimate the serum levels of glucose, insulin, C-peptide and uric acid in patients with psoriasis before and after treatment. The study included 12 males with active form of psoriasis and 15 control subjects carefully matched to the psoriatic patients for age and BMI. All measured parameters were in patients with psoriasis significantly increased and dependent on the BMI. Compared with pretreatment values of glucose and uric acid were significantly lower during therapy. The increase in the mean C-peptide and insulin levels after psoriasis therapy was constant and independent from clinical stage of disease. The results of the present study have provided evidence for the importance of impaired glucose and purine metabolism in patients with psoriasis in the increase risk of development of diabetes mellitus and hypertension.

Purpose: The aim of this study is an estimation of the visual evoked potentials (VEP) in patients with psoriasis vulgaris. The role of the nervous system was pointed out in the pathogenesis of psoriasis. Also epidemiologic research confirms that patients with psoriasis are at increased risk of MS development., Materials and Methods: A group of 30 psoriatic males aged between 18 and 54 was examined. The results were compared with those obtained from a group of 30 healthy age-matched males and they were correlated with the psoriasis area and severity index (PASI), the skin surface area involved, duration of the disease and duration of the last relapse. In neurological and ophthalmological examinations no pathological symptoms were detected in either group. The VEP examination was executed using pattern reversal (pr) and pattern flash (pf) stimulation., Results: Using pf stimulation, in the group of patients with psoriasis vulgaris, a statistically significant elongation in the latency of P-100 and reduction of response amplitude, not related to the PASI, nor the skin surface area involved, nor duration of the last relapse, were observed., Conclusions: The results of the study indicate subclinical damage of the visual pathway in patients with psoriasis vulgaris.

Purpose: The aim of this study is an estimation of the visual evoked potentials (VEP) of persons exposed to prolonged contact with leaded petrol., Materials and Methods: A group of 90 males aged between 22 and 53, exposed to prolonged contact with leaded petrol for the period of between a few months to 30 years, was examined. Those examined were divided into three groups depending on the length of exposure: group 1 up to 10 years, group II-11-20 years, group III-20 years and more. The results were compared with those obtained from a group of 40 healthy age-matched males, not exposed to leaded petrol. In neurological and ophthalmological examinations no pathological symptoms were detected in both groups. The VEP examination was executed using pattern reversal (pr) and pattern flash (pf) stimulation., Results: The frequent pathological record of VEP was an elongation in the latency of P-100 and reduction of response amplitude. Using pr stimulation, the reduction of the mean value of the amplitude for group III was found statistically significant (p < 0.01). In pf examination in group III mean latency of the P-100 was significantly statistically (p < 0.01) longer than in the control group. Significant reduction of the response amplitude in groups II (p < 0.01) and III (p < 0.001) was found in this type of stimulation., Conclusions: The results of studies indicate subclinical damage of the visual pathway particularly of persons exposed to leaded petrol vapour during work for longer than 20 years.

A giant intracranial aneurysm is described in a woman aged 70. CT image suggested an expanding lesion.