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A new class of aluminum homocatenated compounds (Li nAl nH2 n+2) is proposed based on quantum chemical calculations. In these compounds, Al abstracts an electron from Li, becoming valence isoelectronic with C, Si, and Ge, thus mimicking respective structural features of Group 14 hydrides. Using the Coalescence Kick search program coupled with density functional theory calculations, we investigated the potential energy surfaces of Li2Al2H6 and Li3Al3H6. Then single-point-energy coupled-cluster calculations were performed for the lowest energy structures found. Indeed, the global minima established for Li2Al2H6 and Li3Al3H6 contain the Al2H62− and Al3H63− kernels, which are isostructural with ethane (C2H6), disilane (Si2H6), digermane (Ge2H6) and propane (C3H8), trisilane (Si3H8), trigermane (Ge3H8) molecules, respectively. Structural, energetic, and electronic characteristics of the Li2Al2H6 and Li3Al3H8 compounds are presented and the viability of their synthesis is discussed. [ABSTRACT FROM AUTHOR]

A new class of aluminum homocatenated compounds (Li nAl nH2 n+2) is proposed based on quantum chemical calculations. In these compounds, Al abstracts an electron from Li, becoming valence isoelectronic with C, Si, and Ge, thus mimicking respective structural features of Group 14 hydrides. Using the Coalescence Kick search program coupled with density functional theory calculations, we investigated the potential energy surfaces of Li2Al2H6 and Li3Al3H6. Then single-point-energy coupled-cluster calculations were performed for the lowest energy structures found. Indeed, the global minima established for Li2Al2H6 and Li3Al3H6 contain the Al2H62− and Al3H63− kernels, which are isostructural with ethane (C2H6), disilane (Si2H6), digermane (Ge2H6) and propane (C3H8), trisilane (Si3H8), trigermane (Ge3H8) molecules, respectively. Structural, energetic, and electronic characteristics of the Li2Al2H6 and Li3Al3H8 compounds are presented and the viability of their synthesis is discussed. [ABSTRACT FROM AUTHOR]

Based on the Coalescence Kick search program coupled with DFT calculations on the potential energy surfaces of Li2Al2H6 and Li3Al3H6 a new class of homocatenated LinAlnH2n+2 compounds is proposed in which Al abstracts an electron from Li and thus becomes valence isoelectronic with C, Si, and Ge. [ABSTRACT FROM AUTHOR]

Invited for the cover of this issue is Alexander I. Boldyrev and co-workers at Utah State University. The image depicts the magician who symbolizes a chemist synthesizing molecules of 'aluminum homocatenated ethane and propane' based on the idea of electronic transmutation. Read the full text of the article at . [ABSTRACT FROM AUTHOR]

A theoretical prediction of a new class of stable aluminum homocatenated LinAlnH2n+2 compounds is reported by A. I. Boldyrev and co ‐ workers in their Communication on page 5307 ff. For the first time it has been shown that aluminum atoms are capable to homocatenate with the formation of alkane ‐ like species. The wizard shown in the center of the cover picture symbolizes a chemist synthesizing molecules of “aluminum homocatenated ethane and propane” based on the idea of electronic transmutation. [ABSTRACT FROM AUTHOR]

Invited for the cover of this issue is Alexander I. Boldyrev and co-workers at Utah State University. The image depicts the magician who symbolizes a chemist synthesizing molecules of 'aluminum homocatenated ethane and propane' based on the idea of electronic transmutation. Read the full text of the article at . [ABSTRACT FROM AUTHOR]

Two-dimensional (2D) semiconductors exhibit unique physical properties at the limit of a few atomic layers that are desirable for optoelectronic, spintronic, and electronic applications. Some of these materials require ambient encapsulation to preserve their properties from environmental degradation. While encapsulating 2D semiconductors is essential to device functionality, they also impact heat management due to the reduced thermal conductivity of the 2D material. There are limited experimental reports on in-plane thermal conductivity measurements in encapsulated 2D semiconductors. These measurements are particularly challenging in ultrathin films with a lower thermal conductivity than graphene since it may be difficult to separate the thermal effects of the sample from the encapsulating layers. To address this challenge, we integrated the frequency domain thermoreflectance (FDTR) and optothermal Raman spectroscopy (OTRS) techniques in the same experimental platform. First, we use the FDTR technique to characterize the cross-plane thermal conductivity and thermal boundary conductance. Next, we measure the in-plane thermal conductivity by model-based analysis of the OTRS measurements, using the cross-plane properties obtained from the FDTR measurements as input parameters. We provide experimental data for the first time on the thickness-dependent in-plane thermal conductivity of ultrathin MoS 2 nanofilms encapsulated by alumina (Al 2 O 3 ) and silica (SiO 2 ) thin films. The measured thermal conductivity increased from 26.0 ± 10.0 W m -1 K -1 for monolayer MoS 2 to 39.8 ± 10.8 W m -1 K -1 for the six-layer films. We also show that the thickness-dependent cross-plane thermal boundary conductance of the Al 2 O 3 /MoS 2 /SiO 2 interface is limited by the low thermal conductance (18.5 MW m -2 K -1 ) of the MoS 2 /SiO 2 interface, which has important implications on heat management in SiO 2 -supported and encased MoS 2 devices. The measurement methods can be generalized to other 2D materials to study their anisotropic thermal properties.

Background: Despite the widespread institution of modern massive transfusion protocols with balanced blood product ratios, survival for patients with traumatic hemorrhage receiving ultramassive transfusion (UMT) (defined as ≥20 U of packed red blood cells [RBCs]) in 24 hours) remains low and resource consumption remains high. Therefore, we aimed to identify factors associated with mortality in trauma patients receiving UMT in the modern resuscitation era., Methods: An Eastern Association for the Surgery of Trauma multicenter retrospective study of 461 trauma patients from 17 trauma centers who received ≥20 U of RBCs in 24 hours was performed (2014-2019). Multivariable logistic regression and Classification and Regression Tree analysis were used to identify clinical characteristics associated with mortality., Results: The 461 patients were young (median age, 35 years), male (82%), severely injured (median Injury Severity Score, 33), in shock (median shock index, 1.2; base excess, -9), and transfused a median of 29 U of RBCs, 22 U of fresh frozen plasma (FFP), and 24 U of platelets (PLT). Mortality was 46% at 24 hours and 65% at discharge. Transfusion of RBC/FFP ≥1.5:1 or RBC/PLT ≥1.5:1 was significantly associated with mortality, most pronounced for the 18% of patients who received both RBC/PLT and RBC/FFP ≥1.5:1 (odds ratios, 3.11 and 2.81 for mortality at 24 hours and discharge; both p < 0.01). Classification and Regression Tree identified that age older than 50 years, low initial Glasgow Coma Scale, thrombocytopenia, and resuscitative thoracotomy were associated with low likelihood of survival (14-26%), while absence of these factors was associated with the highest survival (71%)., Conclusion: Despite modern massive transfusion protocols, one half of trauma patients receiving UMT are transfused with either RBC/FFP or RBC/PLT in unbalanced ratios ≥1.5:1, with increased associated mortality. Maintaining focus on balanced ratios during UMT is critical, and consideration of advanced age, poor initial mental status, thrombocytopenia, and resuscitative thoracotomy can aid in prognostication., Level of Evidence: Prognostic, level III., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Two-dimensional transitional metal halides have recently attracted significant attention due to their thickness-dependent and electrostatically tunable magnetic properties. However, this class of materials is highly reactive chemically, which leads to irreversible degradation and catastrophic dissolution within seconds in ambient conditions, severely limiting subsequent characterization, processing, and applications. Here, we impart long-term ambient stability to the prototypical transition metal halide CrI 3 by assembling a noncovalent organic buffer layer, perylenetetracarboxylic dianhydride (PTCDA), which templates subsequent atomic layer deposition (ALD) of alumina. X-ray photoelectron spectroscopy demonstrates the necessity of the noncovalent organic buffer layer since the CrI 3 undergoes deleterious surface reactions with the ALD precursors in the absence of PTCDA. This organic-inorganic encapsulation scheme preserves the long-range magnetic ordering in CrI 3 down to the monolayer limit as confirmed by magneto-optical Kerr effect measurements. Furthermore, we demonstrate field-effect transistors, photodetectors, and optothermal measurements of CrI 3 thermal conductivity in ambient conditions.

Introduction: Interestingly, the pediatric and adult surgeons perform vastly different operations in similar patient populations. Little is known about long-term recurrence and quality of life (QOL) in adolescents and young adults undergoing inguinal hernia repair. We evaluated long-term patient-centered outcomes in this population to determine the optimal operative approach., Methods: The medical records of patients 12-25 years old at the time of a primary inguinal hernia repair at our institution from 2000 to 2016 were retrospectively reviewed. Patients then completed a phone survey of their postoperative courses and QOL. Outcomes of high ligation performed by pediatric surgeons were compared to those of mesh repairs by adult general surgeons. The primary outcome was recurrence. Secondary outcomes included time to recurrence, postoperative complications, and patient-centered outcomes. A Cox regression analysis was used to determine associations for recurrence., Results: Of 213 patients identified, 143 (67.1%) were repaired by adult surgeons and 70 (32.9%) repaired by pediatric surgeons. Overall recurrence rate for the entire cohort was 5.7% with a median time to recurrence of 3.5 years (interquartile range 120-2155 days). High ligation and mesh repairs had similar rates of recurrence (6.3 versus 5.8, P = .57) and postoperative complications (17% versus 16%, P = .45). 101/213 (47%) patients completed the phone survey. Of those surveyed, 20% reported postoperative pain, 10% had residual numbness and tingling, and 10% of patients complained of intermittent bulging. Overall, a survey comparison showed no differences among subgroups., Conclusions: In adolescents and young adults, the long-term recurrence rate after inguinal hernia repair is ∼6% with time to recurrence approaching 4 years. Outcomes of high ligation and mesh repair are similar, highlighting the need for individualized approaches for this unique population.

For older drivers, in-vehicle technology offers much potential to improve safety and increase longevity of retaining both licensure and community mobility. However, little is known about how older drivers perceive Advanced Vehicle Technologies (AVTs) based on everyday driving experience. Interviews with 35 older drivers (20 men; 15 women) aged 60-85 who owned a vehicle with at least two AVTs (e.g., back-up camera, lane departure warning) were conducted to explore the meanings that older drivers assigned to AVTs and motivations for use, including whether age-related functional changes were part of their automobile purchase decision. Findings indicate that age-related changes are not a primary reason for why older adults seek out AVTs, but they still perceived and experienced AVTs to counteract age-related changes in driving performance based upon changes they felt occurring within the body. Older drivers also described AVTs as generating a sense of comfort behind-the-wheel. Comfort with this technology was equated with convenience, ease of use, and increased feelings of safety. Discussion emphasizes how assessments of the quality of driving performance and value of technology occur in relation to an aging body., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Background: Suboptimal position of tunneled central venous catheters (Broviacs) decreases long-term catheter longevity, incurring morbidity and cost. We postulated that catheter malposition is related to patient's age, technique used, and initial catheter tip location (CTL)., Methods: We performed a retrospective review with 1-year follow-up of Broviacs placed in patients at our children's hospital from 3/2010 to 10/2013. We defined malposition as a noncentral CTL that required replacement, excluding catheters physically dislodged. We used logistic regression to determine whether age, technique and CTL predicted malposition with p-value<0.05 deemed significant. We analyzed line longevity for different insertion techniques by survival analysis., Results: Overall, 404 upper body Broviacs were placed in 282 children (median age=1.4years [IQR:0.45-5.35]). Thirty-six (8.9%) were replaced for malposition, at median of 84.5days [IQR:36-159]. We found that older children were less likely to develop malposition (OR=0.91,p=0.002). Adjusting for patient age and placement technique, catheters placed ≥1.5 vertebral bodies below the carina were less likely to be malpositioned (OR=0.37,p=0.015). Cox-regression shows the lateral technique to have the lowest rate of malposition within 90days (HR=0.30,p=0.03)., Conclusion: Older patients and lines placed 1.5 vertebral bodies below the carina are less likely to become malpositioned. Using the lateral approach for insertion improves catheter longevity., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Legumes (Fabaceae or Leguminosae) are unique among cultivated plants for their ability to carry out endosymbiotic nitrogen fixation with rhizobial bacteria, a process that takes place in a specialized structure known as the nodule. Legumes belong to one of the two main groups of eurosids, the Fabidae, which includes most species capable of endosymbiotic nitrogen fixation. Legumes comprise several evolutionary lineages derived from a common ancestor 60 million years ago (Myr ago). Papilionoids are the largest clade, dating nearly to the origin of legumes and containing most cultivated species. Medicago truncatula is a long-established model for the study of legume biology. Here we describe the draft sequence of the M. truncatula euchromatin based on a recently completed BAC assembly supplemented with Illumina shotgun sequence, together capturing ∼94% of all M. truncatula genes. A whole-genome duplication (WGD) approximately 58 Myr ago had a major role in shaping the M. truncatula genome and thereby contributed to the evolution of endosymbiotic nitrogen fixation. Subsequent to the WGD, the M. truncatula genome experienced higher levels of rearrangement than two other sequenced legumes, Glycine max and Lotus japonicus. M. truncatula is a close relative of alfalfa (Medicago sativa), a widely cultivated crop with limited genomics tools and complex autotetraploid genetics. As such, the M. truncatula genome sequence provides significant opportunities to expand alfalfa's genomic toolbox.

Background Context: Access to care for poor/near poor patients is a concerning and growing problem within the American system of medical care., Purpose: The objective of this study was to examine the relationship between health insurance status and access to spine care among patients below 65 years of age eventually receiving treatment at our tertiary academic medical center., Study Design: Descriptive study based on chart review and telephone interviews., Patient Sample: Two groups of 64 patients each with surgical pathology of limited complexity and limited comorbidities, one with Medicaid insurance and one with private, commercial insurance., Outcome Measures: Reasons for referral, travel distance, travel time, frequency of visits, and proximity of fellowship-trained spinal surgeons., Methods: Two groups, each with 64 consecutive spine surgical patients, were studied and compared. Group One had "Medicaid" coverage and Group Two was privately insured. All patients (both groups) were treated surgically for similar pathology of limited complexity and had limited comorbidities. They were assessed to determine the difficulties they encountered in receiving care before referral to our medical center including factors such as referral by a local provider based on insurance status alone and travel time/distance/frequency to eventually receive care at our center. The availability of local care for these patients (fellowship-trained spine surgeons in their local area) was also assessed., Results: The great majority (78%) of poor/near poor patients with Medicaid coverage from counties at some distance from (and local to) our center were referred/deferred on the basis of insurance status alone given surgical problems which could have comfortably been addressed by orthopedic surgeons, neurosurgeons, or fellowship-trained spine surgeons local to the patient. This difficulty in access to care results in a significant burden (measured in time/travel/costs) for these patients., Conclusions: The poor/near poor with Medicaid insurance have less access to local spine care than those with private, commercial health insurance. The implications (from both surgeon and patient perspectives) of this dilemma are discussed.

Microsatellites are tandemly repeated short DNA sequences that are favored as molecular-genetic markers due to their high polymorphism index. Plant genomes characterized to date exhibit taxon-specific differences in frequency, genomic location, and motif structure of microsatellites, indicating that extant microsatellites originated recently and turn over quickly. With the goal of using microsatellite markers to integrate the physical and genetic maps of Medicago truncatula, we surveyed the frequency and distribution of perfect microsatellites in 77 Mbp of gene-rich BAC sequences, 27 Mbp of nonredundant transcript sequences, 20 Mbp of random whole genome shotgun sequences, and 49 Mbp of BAC-end sequences. Microsatellites are predominantly located in gene-rich regions of the genome, with a density of one long (i.e., > or = 20 nt) microsatellite every 12 kbp, while the frequency of individual motifs varied according to the genome fraction under analysis. A total of 1,236 microsatellites were analyzed for polymorphism between parents of our reference intraspecific mapping population, revealing that motifs (AT)n, (AG)n, (AC)n, and (AAT)n exhibit the highest allelic diversity. A total of 378 genetic markers could be integrated with sequenced BAC clones, anchoring 274 physical contigs that represent 174 Mbp of the genome and composing an estimated 70% of the euchromatic gene space.

An international consortium is sequencing the euchromatic genespace of Medicago truncatula. Extensive bioinformatic and database resources support the marker-anchored bacterial artificial chromosome (BAC) sequencing strategy. Existing physical and genetic maps and deep BAC-end sequencing help to guide the sequencing effort, while EST databases provide essential resources for genome annotation as well as transcriptome characterization and microarray design. Finished BAC sequences are joined into overlapping sequence assemblies and undergo an automated annotation process that integrates ab initio predictions with EST, protein, and other recognizable features. Because of the sequencing project's international and collaborative nature, data production, storage, and visualization tools are broadly distributed. This paper describes databases and Web resources for the project, which provide support for physical and genetic maps, genome sequence assembly, gene prediction, and integration of EST data. A central project Web site at medicago.org/genome provides access to genome viewers and other resources project-wide, including an Ensembl implementation at medicago.org, physical map and marker resources at mtgenome.ucdavis.edu, and genome viewers at the University of Oklahoma (www.genome.ou.edu), the Institute for Genomic Research (www.tigr.org), and Munich Information for Protein Sequences Center (mips.gsf.de).

Although the expression and function of CD40 on B lymphocytes has been well studied, the significance of CD40 on non-lymphoid cells such as keratinocytes (KC) is not as well characterized. We demonstrate in this report that CD40 is expressed by virtually all human KC, and that it functions as an important signaling molecule. Flow cytometry of undifferentiated and terminally differentiated KC indicated that both cell types expressed CD40, as determined by binding to monoclonal antibodies and a recombinant CD40 ligand fusion protein; interferon-gamma (IFN-gamma) treatment of KC increased CD40 expression. Cultured KC also expressed 1.5-kb CD40 transcripts. Activation of KC cell surface CD40 using the monoclonal antibody G28.5 resulted in the rapid generation of a 50-kDa tyrosine phosphorylated polypeptide, as well as a dose-dependent increase in the secretion of interleukin-6, a cytokine that has been linked to KC proliferation. KC also co-stimulated a significant T lymphocyte proliferative response to the mitogen phytohemagglutinin that was CD40 dependent. These data indicate that KC constitutively express a low level of functional CD40 and regulate their expression in response to IFN-gamma. These data support the concept that KC, via their expression of CD40, have the capacity to amplify inflammation in the skin by interacting with CD40 ligand-bearing T cells.