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Objective The Surgical Skills and Technology Elective Program (SSTEP) is a one-week, simulation-based procedural skills bootcamp for preclinical medical students. Using cognitive load (CL) as a useful framework for understanding simulation in medical education, our aims were to (1) examine the ability of SSTEP to decrease medical students’ CL during procedural skills training and (2) determine the impact of SSTEP on secondary learning. Methods In this prospective cohort study, twenty SSTEP participants and twenty controls were recruited. CL was assessed during a simple suturing task and a clinical vignette multitasking activity, where participants were required to suture and concurrently listen to a clinical vignette. CL was measured using the validated Subjective Rating of Mental Effort (SRME) and its impact on working memory was assessed using a knowledge test about the clinical vignette. Results Participants reported lower SRME scores while suturing following SSTEP, which persisted at 3 months (p = 0.002) and were significantly lower than controls (p = 0.031). Participants also reported lower SRME scores during the clinical vignette multitasking activity (p = 0.011), despite no improvement among controls (p = 0.63). Participants significantly outperformed controls on the clinical vignette knowledge test (p = 0.02). Conclusions Surgical skills training through SSTEP was associated with lower reports of mental effort and increased performance on secondary learning tasks. Procedural skills bootcamps may better prepare students for the complex learning environments encountered during clinical clerkship.

Abstract The COVID-19 pandemic triggered a surge in demand for N95 or equivalent respirators that the global supply chain was unable to satisfy. This shortage in critical equipment has inspired research that addresses the immediate problems and has accelerated the development of the next-generation filtration media and respirators. This article provides a brief review of the most recent work with regard to face respirators and filtration media. We discuss filtration efficiency of the widely utilized cloth masks. Next, the sterilization of and reuse of existing N95 respirators to extend the existing stockpile is discussed. To expand near-term supplies, optimization of current manufacturing methods, such as melt-blown processes and electrospinning, has been explored. Future manufacturing methods have been investigated to address long-term supply shortages. Novel materials with antiviral and sterilizable properties with the ability for multiple reuses have been developed and will contribute to the development of the next generation of longer lasting multi-use N95 respirators. Finally, additively manufactured respirators are reviewed, which enable a rapidly deployable source of reusable respirators that can use any filtration fabric. Graphic abstract

Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal malignancy with a 5-year survival rate of 11%. PDAC has limited response to current cytotoxic, targeted and immunotherapies. Thus, it is crucial to explore the molecular underpinnings of this disease in order to identify expression patterns and intercellular dialogue that are limiting the effectiveness of current therapies. Here, we dissected the single-cell spatial transcriptomic landscape of untreated (n=7) and treated (chemoradiation, n=7) primary resected human PDAC tumors using spatial molecular imaging with a custom 990-plex panel. We recovered 719,965 high-quality single cells of 20 distinct types, including epithelial, immune, endothelial, endocrine, and diverse stromal cells. We further dissected the malignant, cancer-associated fibroblasts (CAF), and endothelial cells by applying single-nucleus RNA sequencing (snRNA-seq)-derived signatures. We explored how treatment altered the intraglandular heterogeneity of malignant programs and intratumoral composition of multicellular neighborhoods, for which we developed a Gaussian-based computational model. In concordance with previous studies, we found that myofibroblastic CAFs spatially localized with malignant cells. Treatment-enriched neural-like progenitor malignant cells spatially localized with CD8+ T cells, which combined with other findings suggests that different malignant subtypes may employ distinct mechanisms of immune evasion. We further investigated receptor-ligand interactions associated with therapeutic resistance at subcellular spatial resolution. To this end, we developed an optimal transport-based computational method to infer cell-cell communication at the cancer-stromal interface. We functionally validated a subset of predicted interactions using a murine stromal tumoroid model, in which we co-cultured transformed pancreatic ductal cells and CAFs in a solubilized extracellular matrix. We evaluated the strength of predicted interactions in response to ex vivo chemotherapy using snRNA-seq. Moreover, we modulated the expression of select ligand-receptor pairs in the malignant-CAF co-cultures using CRISPR-mediated genetic engineering. We tested the effects of these perturbations on therapeutic resistance using cell viability assays, including live-cell label-free phase nanoscopy. In conclusion, we integrated single-cell spatial transcriptomics and novel computational methods to identify mechanisms of therapeutic resistance in PDAC at both cellular and molecular levels. We functionally validated a subset of cancer-stromal receptor-ligand interactions predicted to associate with treatment resistance using genetically-engineered stromal tumoroids, demonstrating the translational potential of spatial biology for guiding therapeutic development. Citation Format: Carina Shiau, Jingyi Cao, Mark Gregory, Tae Kyung Kim, Youngmi Kim, Jason W. Reeves, Peter L. Wang, Steven Wang, Nicole A. Lester, Jennifer Su, Jimmy Guo, Joseph M. Beechem, David T. Ting, Martin Hemberg, William L. Hwang. Mechanisms of therapeutic resistance in pancreatic cancer identified by single-cell spatial transcriptomics and genetically-engineered stromal tumoroids [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1165.

Pancreatic ductal adenocarcinoma (PDAC) features abundant perineural invasion (PNI). Intra-tumoral nerves play critical roles in cancer initiation, progression, recurrence, treatment-resistance, metastasis, and mortality for many malignancies but the diverse molecular mechanisms underlying tumor-nerve crosstalk remain largely unknown—hindering the development of therapies targeting this key pathological process. To address this gap, we performed whole transcriptome digital spatial profiling on twelve custom tissue microarrays (n=288 cores) derived from intratumorally-matched regions with and without PNI in primary PDAC specimens (n=31 patients) and independently measured gene expression from cancer cells, fibroblasts, and nerves. We undertook a differential gene expression analysis comparing malignant cells in PNI-present and -absent regions. We quantified the growth kinetics of dorsal root ganglia (DRG) sensory neurons cultured with exogenous candidate proteins, which validated that some candidates augment (e.g., Lgals1) and others inhibit (e.g., Sema3b) neurite outgrowth. Next, we mapped our previously discovered malignant cell programs onto the epithelial segments and observed a significant enrichment of the mesenchymal, basal-like, and neural-like progenitor (NRP) programs versus depletion of the classical program in PNI-present regions. To determine the effects of malignant subtype on nerve outgrowth, we engineered isogenic KrasG12D/+;Trp53FL/FL;Rosa26-dCas9-VPR (KP;dCas9-VPR) organoids to overexpress the master transcription factors (TFs) for each malignant subtype (e.g., Gata6 for classical, Glis3 for NRP). We then performed the DRG neuronal outgrowth assay using conditioned media from each subtype-specific organoid line versus an off-target control and observed that the classical line suppressed neurite outgrowth, the mesenchymal and basal-like lines were neutral, and the NRP line enhanced neurite outgrowth dynamics comparable to the Ngf positive control. Taken together, our findings suggest that the mechanisms underlying nerve recruitment/outgrowth and perineural invasion may be partly decoupled. To further test this hypothesis, we are performing transwell invasion assays comparing KP;dCas9-VPR cancer cell lines that overexpress each of the candidate PNI-associated genes and malignant subtype TFs. We anticipate that this study will transform our understanding of how cancer cells and the peripheral nervous system collaborate and guide prioritization for therapeutic intervention in the burgeoning cancer neuroscience field. Citation Format: William L. Hwang, Jennifer Su, Carina Shiau, Peter L. Wang, Jimmy A. Guo, Nicole A. Lester, Jaimie L. Barth, Hannah I. Hoffman, Prajan Divakar, Jason W. Reeves, Eric Miller, Joseph M. Beechem, Andrew J. Aguirre, Lei Zheng, David T. Ting, Mari Mino-Kenudson, Tyler Jacks. Distinct cancer-intrinsic mechanisms mediate nerve recruitment/outgrowth versus perineural invasion [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2513.

The peripheral nerve contains diverse cell types that support its proper function and maintenance. We analyzed multiple peripheral nerves using single-nuclei RNA-sequencing (snRNA-seq), which allowed us to circumvent difficulties encountered in analyzing cells with complex morphologies via conventional single cell methods. The resultant mouse peripheral nerve cell atlas highlights a diversity of cell types, including multiple subtypes of Schwann cells (SCs), immune cells, and stromal cells. We identified a distinct myelinating-SC subtype that expresses Cldn14, Adamtsl1, and Pmp2 and preferentially ensheathes motor axons. The number of these motor-associated, Pmp2(+) SCs is reduced in both ALS SOD1(G93A) mouse model and human ALS nerve samples. Our findings reveal the diversity of SCs and other cell types in peripheral nerve and serve as a reference for future studies of nerve biology and disease.

Barrier tissue immune responses are regulated, in part, by nociceptors. Nociceptor ablation alters local immune responses at peripheral sites and within draining lymph nodes (LNs). Nevertheless, the mechanisms and significance of nociceptor-dependent modulation of LN function are unknown. Using high-resolution imaging, viral tracing, single-cell transcriptomics, and optogenetics, we identified and functionally tested a sensory neuro-immune circuit that is responsive to lymph-borne inflammatory signals. Transcriptomic profiling revealed that multiple sensory neuron subsets – predominantly peptidergic nociceptors – innervate LNs, distinct from those innervating surrounding skin. To uncover LN-resident cells that may interact with LN-innervating sensory neurons, we generated a LN single-cell transcriptomic atlas and nominated nociceptor target populations and interaction modalities. Optogenetic stimulation of LN-innervating sensory fibers triggered rapid transcriptional changes within the predicted interacting cell types, particularly endothelium, stromal cells, and innate leukocytes. Thus, a unique population of sensory neurons monitors peripheral LNs and may locally regulate gene expression.

Concrete additive manufacturing (AM) is a growing field of research. However, on-site, large-scale concrete additive manufacturing requires motion platforms that are difficult to implement with conventional rigid-link robotic systems. This article presents a new kinematic arrangement for a deployable cable-driven robot intended for on-site AM. The kinematics of this robot are examined to determine if they meet the requirements for this application, the wrench feasible workspace (WFW) is examined, and the physical implementation of a prototype is also presented. Data collected from the physical implementation of the proposed system are analyzed, and the results support its suitability for the intended application. The success of this system demonstrates that this kinematic arrangement is promising for future deployable AM systems.

The extent splicing is regulated at single-cell resolution has remained controversial due to both available data and methods to interpret it. We apply the SpliZ, a new statistical approach, to detect cell-type-specific splicing in >110K cells from 12 human tissues. Using 10X Chromium data for discovery, 9.1% of genes with computable SpliZ scores are cell-type-specifically spliced, including ubiquitously expressed genes MYL6 and RPS24. These results are validated with RNA FISH, single-cell PCR, and Smart-seq2. SpliZ analysis reveals 170 genes with regulated splicing during human spermatogenesis, including examples conserved in mouse and mouse lemur. The SpliZ allows model-based identification of subpopulations indistinguishable based on gene expression, illustrated by subpopulation-specific splicing of classical monocytes involving an ultraconserved exon in SAT1. Together, this analysis of differential splicing across multiple organs establishes that splicing is regulated cell-type-specifically.

Cirrhosis is a major risk factor for developing hepatocellular carcinoma (HCC). However, many surgically resected HCCs are presumably non-cirrhotic. The dynamic nature of chronic liver disease leads to periods of hepatic repair and fibrosis regression. We hypothesize that most resected HCCs, including those from non-cirrhotic patients, exhibit features of fibrosis regression in their background liver, suggesting previously more advanced liver disease. We reviewed the histology of 37 HCC resections performed between 2005–2020, including 30 from non-cirrhotic patients. The non-neoplastic liver was evaluated for features of liver disease and of the hepatic repair complex (HRC). CD34 immunohistochemistry was performed as a marker of sinusoidal capillarization. CD34 staining was evaluated manually and also by a digital image classifier algorithm. Overall, 28 cases (76%) had a high number of fibrosis regression and hepatic repair features (≥4 out of 8 features). Amongst the 30 non-cirrhotic patients, 21 (70%) showed a high number of repair features. Relative CD34 expression was increased in cases with a high number (≥4) of HRC features versus a low number (≤3) of features (p = 0.019). High HRC cases were more likely to exhibit nodular circumferential CD34 staining (p = 0.019). Our findings suggest that most resected HCC from non-cirrhotic patients display features of fibrosis regression in their background liver. Thus many, if not most, HCC patients who are “non-cirrhotic” may in fact have regressed cirrhosis. This finding reinforces that patients with regressed cirrhosis continue to be at high risk for HCC.

Rationale & Objective The decision to initiate kidney replacement therapy (KRT) for acute kidney injury (AKI) in cirrhosis remains controversial as it is unclear which patients will benefit. We sought to characterize factors associated with recovery from AKI requiring KRT in patients with cirrhosis to inform shared clinical decision-making. Study Design Population-based retrospective cohort study. Setting & Participants Adult patients from Ontario, Canada identified, using administrative data, to have cirrhosis at the time of admission to hospital with AKI (based on serum creatinine) requiring KRT (01/01/2009–12/31/2016) and followed until 12/31/2017. Exposures Demographics and comorbidities prior to admission. Outcomes Kidney recovery defined as the absence of KRT for at least 30 days. Analytical Approach The cumulative incidences of kidney recovery, death, and liver transplantation were calculated at 1, 3, 6, and 12 months and independent predictors of kidney recovery were evaluated using Fine and Gray competing risk regression models that generated subdistribution hazards ratios (sHR). Results Overall, 722 patients were included (median age 61 years [IQR 54-68]; MELD-Na 26 [IQR 22-34]; 66% male; 52% had viral hepatitis, 25% non-alcoholic fatty liver disease, 18% alcohol-associated liver disease). The cumulative incidences of kidney recovery at 1, 3, 6, and 12 months were 3%, 22%, 25%, and 26%, respectively. Higher MELD-Na score (sHR 0.72 per 5 units, 95%CI 0.65-0.80), acute-on-chronic liver failure (sHR 0.61, 95%CI 0.43-0.86), and sepsis (sHR 0.57, 95%CI 0.41-0.81) were associated with a lower hazard of kidney recovery while those on a liver transplant waitlist (sHR 3.10, 95% CI 1.96-4.88) and who were admitted to a teaching hospital (sHR 1.48, 95%CI 1.05-2.08) were more likely to experience kidney recovery. Limitations Observational design, AKI etiology not identified. Conclusions Kidney recovery from KRT occurred in only one-quarter of patients and was very unlikely after 3-months. These findings provide information regarding prognosis that may guide decisions regarding KRT initiation and continuation.

More than 95% of human genes are alternatively spliced. Yet, the extent splicing is regulated at single-cell resolution has remained controversial due to both available data and methods to interpret it. We apply the SpliZ, a new statistical approach that is agnostic to transcript annotation, to detect cell-type-specific regulated splicing in > 110K carefully annotated single cells from 12 human tissues. Using 10x data for discovery, 9.1% of genes with computable SpliZ scores are cell-type specifically spliced. These results are validated with RNA FISH, single cell PCR, and in high throughput with Smart-seq2. Regulated splicing is found in ubiquitously expressed genes such as actin light chain subunit MYL6 and ribosomal protein RPS24, which has an epithelial-specific microexon. 13% of the statistically most variable splice sites in cell-type specifically regulated genes are also most variable in mouse lemur or mouse. SpliZ analysis further reveals 170 genes with regulated splicing during sperm development using, 10 of which are conserved in mouse and mouse lemur. The statistical properties of the SpliZ allow model-based identification of subpopulations within otherwise indistinguishable cells based on gene expression, illustrated by subpopulations of classical monocytes with stereotyped splicing, including an un-annotated exon, in SAT1, a Diamine acetyltransferase. Together, this unsupervised and annotation-free analysis of differential splicing in ultra high throughput droplet-based sequencing of human cells across multiple organs establishes splicing is regulated cell-type-specifically independent of gene expression.

Calculated profile mode mass spectrometry (MS) data are fitted to lineshape-calibrated liquid chromatography LC/MS data using a Multiple Linear Regression (MLR) model to quantitate the relative concentrations of stable or radiolabeled compound mixtures. This alternative approach significantly improves the precision and accuracy over existing MS methods while providing the much-needed statistical diagnostics on the goodness-of-fit model and thus reliability of the quantitative results obtained. Test compound data containing S/Cl atoms have been measured with either stable deuterium labeling or radioisotope uniform 14 C labeling onto an aromatic ring. Since the entire relative distribution of variously labeled compounds is automatically obtained through this approach, it is feasible to directly calculate the Specific Activity (SA) from such mass spectral analysis without radioactivity detection and the usual standard curve quantitation. The applicability of this approach to systematically and accurately accommodate and account for incomplete labeling chemistry or other impurities is also discussed, with wide-ranging implications including metabolic flux, HDX (Hydrogen/Deuterium Exchange), and quantitative proteomics.

We examine how broadband impacts entrepreneurship, income, and employment in the United States from 2000 to 2019, specifically the differential impacts for women and minorities. Using Current Population Surveys Computer and Internet Use Supplement and matching, we find that home broadband access significantly impacted the decision to be self-employed from the early years of broadband until at least 2012. Broadband access also had an impact on reducing unemployment, being particularly effective for minority males and females during the recovery period of the Great Recession. Broadband access also raised weekly earnings and entrepreneurial income. In more recent years, the benefits of owning broadband access for increasing entrepreneurship, avoiding unemployment, and raising income have diminished, but home broadband access leads to a higher propensity of holding more than one job.

Tertiary lymphoid organs often arise during chronic inflammation, including in inflammatory bowel diseases like ileitis. The impact of TLOs on disease progression or immunity and how they integrate with or influence the surrounding tissue microenvironment remain unclear. In human Crohn's disease, we earlier observed that TLOs were positioned along mesenteric collecting lymphatic vessels (CLVs) that govern lymph outflow from the intestine. Here we show in the TNFΔARE mouse model of Crohn’s-like ileitis that TLOs form at valve regions of CLVs, supporting lymphangiogenic outgrowths. These TLOs compress CLVs, preventing forward lymph flow and immune cell egress to draining lymph nodes, while fostering lymph leak and backflow. Lymph transport through TLOs was restored if TNF neutralization was begun early. However, robustly developed TLOs resisted regression and restoration of flow. Thus, TLOs can profoundly remodel communication between tissues and their draining lymph nodes by strongly suppressing dissemination of cells and molecules.

We examine how component changes affect network value. Theory indicates that increased component value can increase sales for network access. Using a panel of countries from 2003-2017, we test this by analyzing how the iPhone’s introduction in 2007 affected mobile broadband adoption. We find the iPhone and its imitators explain 60% of the average rise in mobile broadband’s growth rate. Per capita GDP mattered in developed, but not developing countries. The quality of government mattered in both types of countries, but regulation mattered more in developed countries, while rule of law mattered more in developing countries.

A major challenge with Competency Based Medical Education (CBME) is that of increased assessment burden on faculty. To reduce this burden, the accuracy and reliability of peer-assessment for surgical skills requires further exploration.Forty-two second year medical students were video recorded while performing a simple interrupted suture and an instrument tie. Four novice raters underwent a short training session on the use of the Objective Structured Assessment of Technical Skills (OSATS) checklists. Videos of the suturing task were then independently assessed by the four novice raters and two expert raters on two occasions. Agreement between novice and expert rater scores was calculated using the intraclass correlation coefficient (ICC).For both simple interrupted suturing (ICC = 0.78, CI = 0.66-0.86, p 0.001) and instrument ties (ICC = 0.87, CI = 0.80-0.92, p 0.001), there was good agreement between novice and expert raters.Novice raters can be taught to use the OSATS checklists to assess peers on simple suturing and instrument tying tasks.

Construction is filled with labor intensive, hazardous, and often wasteful processes. It is also an enormous industry, so improvements in efficiency could have a tremendous economic impact. Construction-scale additive manufacturing is one path toward achieving those improvements. In this paper, a construction-scale additive manufacturing system, called Sky-BAAM, is presented. In addition to possibly leading to more energy-efficient construction practices, leveraging additive manufacturing in construction opens the solution space to more energy efficient building design. One such design, the EMPOWER wall, is also presented in this paper. The exterior of the wall is shaped to maximize heat transfer, while acting as form work for an internal energy-storage system. This allows energy to be stored in the wall during off-peak times and retrieved during peak periods.

We examine how the Coronavirus pandemic affected consumer valuation of digital services. Governments responded to the pandemic with various forms of lockdowns and social distancing, leading to increased dependence on digital services for work, social engagement, and leisure activities. We identify consumer valuations through surveys where respondents express their reservation prices for digital services such as email, search, and social media. We compare our results to surveys done in 2016 and 2017 and find an about five-fold increase in valuations.

We dissect metabolic variability of mononuclear phagocyte (MNP) subpopulations across different tissues through integrative analysis of three large scale datasets. Specifically, we introduce ImmGen MNP Open Source dataset that profiled 337 samples and extended previous ImmGen effort which included 202 samples of mononuclear phagocytes and their progenitors. Next, we analysed Tabula Muris Senis dataset to extract data for 51,364 myeloid cells from 18 tissues. Taken together, a compendium of data assembled in this work covers phagocytic populations found across 38 different tissues. To analyse common metabolic features, we developed novel network-based computational approach for unbiased identification of key metabolic subnetworks based on cellular transcriptional profiles in large-scale datasets. Using ImmGen MNP Open Source dataset as baseline, we define 9 metabolic subnetworks that encapsulate the metabolic differences within mononuclear phagocytes, and demonstrate that these features are robustly found across all three datasets, including lipid metabolism, cholesterol biosynthesis, glycolysis, and a set of fatty acid related metabolic pathways, as well as nucleotide and folate metabolism. We systematically define major features specific to macrophage and dendritic cell subpopulations. Among other things, we find that cholesterol synthesis appears particularly active within the migratory dendritic cells. We demonstrate that interference with this pathway through statins administration diminishes migratory capacity of the dendritic cells in vivo. This result demonstrates the power of our approach and highlights importance of metabolic diversity among mononuclear phagocytes.

We examine how the Coronavirus pandemic affected consumer valuation of digital services. Governments responded to the pandemic with various forms of lockdowns and social distancing, leading to increased dependence on digital services for work, social engagement, and leisure activities. We identify consumer valuations through surveys where respondents express their reservation prices for digital services such as email, search, and social media. We compare our results to surveys done in 2016 and 2017 and find an about five-fold increase in valuations.

We examine people’s tendencies to stay at home and go to traditional places of work during the early stages of the pandemic in the United States. We found no statistically significant impact of home broadband on people’s tendency to stay at home. We did find home broadband to have a small, but statistically significant negative impact on people’s tendency to go to their traditional workplaces. Age demographics, household income, college education, proportion of blue-collar jobs, and metropolitan status were more important factors in explaining people’s tendencies to stay in lockdown.

SummaryWhereas microglia are recognized as fundamental players in central nervous system (CNS) development and function, much less is known about macrophages of the peripheral nervous system (PNS). Here we show that self-maintaining PNS macrophages share unique features with CNS microglia. By comparing gene expression across neural and conventional tissue-resident macrophages, we identified transcripts that were shared among neural resident macrophages as well as selectively enriched in PNS macrophages. Remarkably, PNS macrophages constitutively expressed genes previously identified to be upregulated by activated microglia during aging or neurodegeneration. Several microglial activation-associated and PNS macrophage-enriched genes were also expressed in spinal cord microglia at steady state. While PNS macrophages arose from both embryonic and hematopoietic precursors, their expression of activation-associated genes did not differ by ontogeny. Collectively, these data uncover shared and unique features between neural resident macrophages and emphasize the role of nerve environment for shaping PNS macrophage identity.

Summary Lymphangitis and the formation of tertiary lymphoid organs (TLOs) in the mesentery are features of Crohn’s disease. Here, we examined the genesis of these TLOs and their impact on disease progression. Whole-mount and intravital imaging of the ileum and ileum-draining collecting lymphatic vessels (CLVs) draining to mesenteric lymph nodes from TNFΔARE mice, a model of ileitis, revealed TLO formation at valves of CLVs. TLOs obstructed cellular and molecular outflow from the gut and were sites of lymph leakage and backflow. Tumor necrosis factor (TNF) neutralization begun at early stages of TLO formation restored lymph transport. However, robustly developed, chronic TLOs resisted regression and restoration of flow after TNF neutralization. TNF stimulation of cultured lymphatic endothelial cells reprogrammed responses to oscillatory shear stress, preventing the induction of valve-associated genes. Disrupted transport of immune cells, driven by loss of valve integrity and TLO formation, may contribute to the pathology of Crohn’s disease.

At the onset of the COVID-19 (Coronavirus Disease 2019) pandemic, USA faced supply chain issues causing a nationwide shortage of N95 respirators and PAPR devices. Researchers at Oak Ridge National Laboratory's (ORNL) Manufacturing Demonstration Facility (MDF) were sent to work from home to help slow the spread of the pandemic, and during that time they were tasked with using their manufacturing expertise to research alternative methods of producing face masks. To rapidly iterate on face mask designs without access to a research or manufacturing facility, 3D (3-Dimensional) printing and silicone casting were used. Molds and components for the masks are modeled with computer-aided design (CAD), printed with common home desktop 3D printers, and test poured with skin-safe silicone rubber. The resultant masks are form fitting and comfortable to wear. To ease the shortage of N95 filter media, the masks are designed to use existing filter materials such as home HVAC (heating, ventilation, and air conditioning) filters. The masks can be sanitized, and the filter replaced to allow the same mask to be reused. The result is not equivalent to an N95 mask, and not meant to be a replacement, but is meant to be a stopgap mask that is still able to provide the wearer filtered protection. Filtration testing has not been performed because it is not the intention of the authors to make medical claims. This research is meant to demonstrate the rapid design, iteration, and manufacturing processes of a stopgap mask.

Pioneer reports of Crohn’s disease (CD) suggested that impaired lymphatic flow might drive its pathogenesis but remains unsettled. Nodules of tertiary lymphoid organs (TLO) are found in association with collecting lymphatic vessels (CLVs) of the mesentery that normally conducts lymph outflow from the intestine. Whether TLOs affect lymph transport is unknown. In the TNFΔARE mouse model of Crohn’s-like ileitis, TLOs are found in valves regions. Using lymphatic reporters and photoconversion to study cell trafficking from the intestine, our findings indicated that TLOs halts immune cells traveling from the inflamed ileum to the lymph node, effectively trapping DCs, B, and T cells, and impacting the development of microbe tolerogenic regulatory T cells. Lymphatic transport defects were intrinsic to the CLVs because the soluble fluorescent tracer’s passage through TLO was also blocked. Lymph blockage promoted retrograde lymphatic flow returning towards the gut wall due to incapable valves. Moreover, significant lymph leakage was found, specifically at the TLOs. Neutralizing anti-TNF mAb treatment into TNFΔARE mice is ineffective in eliminating TLOs or restoring lymphatic trafficking when administered in female mice with advanced disease. In males, the therapy was able to restore forward flow to the lymph node. However, even in the presence of TNF inhibition, both sexes demonstrated TLO lymph leakage. Thus, mesenteric TLOs that form during chronic ileitis drive broadly impaired lymph transit of molecules and cells from the intestine that is only partially reversible by neutralizing the cytokine cascade underlying the disease and establish a perennial tissue alteration.

AimsThis review and meta-analysis aim to estimate the cumulative incidence of clozapine induced agranulocytosis and leukopenia the impact of the associated factors such as dose of clozapine, duration of follow-up, gender and race on the cumulative incidence.BackgroundClozapine is the only medication licensed for treatment-resistant schizophrenia. There has been a renewed interest in the role of Clozapine in the treatment of Schizophrenia based on strong evidence that favours its efficacy and safety. Despite the evidence that Clozapine has superior efficacy and has been recommended for treatment-resistant cases by the national guidelines, the drug is underutilised.MethodWe included all studies in which clozapine was used for a psychotic illness. We included studies which provided data on two primary indices; Leucopenia or agranulocytosis and neutropenia; defined according to the cut off used by CPMS for total WBC and neutrophil count. Additionally we included studies reporting another blood dyscrasia or death due to agranulocytosis. Studies were identified by searching AMED, BIOSIS, CINAHL, EMBASE, MEDLINE, PsycINFO, PubMed, and registries of Clinical Trials and their monthly updates, hand searches, gray literature, and conference proceedings from the first available date until 2nd February, 2015. The search was updated on 15th March, 2017. The Protocol was initiated and then registered with PROSPERO International prospective register of systematic reviews University of York, Centre for Reviews and Dissemination.ResultThe cumulative incidence of the agranulocytosis in all studies was 00.32 % (CI 00.1-0.63). The cumulative incidence in all studies for different types of blood dyscrasia were following: leucopenia 00.96 % (CI 0.39-1.70), neutropenia 2.93 % (CI 1.49-4.72), other blood dyscrasias 4.64% (CI 2.34-7.52) and any blood dyscrasia was 2.23 (CI 1.46-3.12).ConclusionThe limitations of this review are mainly due to the nature of evidence from the included studies. We adopted a broad inclusion criteria to include all the available evidence. Number of patients started on Clozapine may be withdrawn from the Clozapine on the earliest signs of blood dyscrasias since the introduction of Clozapine monitoring services. This means that the true incidence of agranulocytosis and neutropenia may be higher and this may be a major bias in finding the true incidence of Clozapine induced neutropenia.

Early pathological descriptions of Crohn disease (CD) argued for a potential defect in lymph transport; however, this concept has not been thoroughly investigated. In mice, poor healing in response to infection-induced tissue damage can cause hyperpermeable lymphatic collecting vessels in mesenteric adipose tissue that impair antigen and immune cell access to mesenteric lymph nodes (LNs), which normally sustain appropriate immunity. To investigate whether analogous changes might occur in human intestinal disease, we established a three-dimensional imaging approach to characterize the lymphatic vasculature in mesenteric tissue from controls or patients with CD. In CD specimens, B-cell-rich aggregates resembling tertiary lymphoid organs (TLOs) impinged on lymphatic collecting vessels that enter and exit LNs. In areas of creeping fat, which characterizes inflammation-affected areas of the bowel in CD, we observed B cells and apparent innate lymphoid cells that had invaded the lymphatic vessel wall, suggesting these cells may be mediators of lymphatic remodeling. Although TLOs have been described in many chronic inflammatory states, their anatomical relationship to preestablished LNs has never been revealed. Our data indicate that, at least in the CD-affected mesentery, TLOs are positioned along collecting lymphatic vessels in a manner expected to affect delivery of lymph to LNs.

The quality of cardiopulmonary resuscitation (CPR) is associated with the probability of survival in people experiencing sudden cardiac arrest.1 Features of CPR quality associated with clinical outcomes include compression rate, compression depth and compression fraction (the proportion of time during a resuscitation attempt when chest compressions are being provided). Evidence suggests that chest compression quality can suffer because of suboptimal team leadership, provider fatigue or distraction with other resuscitation activities (eg, airway management, patient transfer, pulse checks).1 Mechanical chest compression devices have been developed to provide more consistent high quality chest compressions. Devices available on the market today use one of two fundamental mechanisms to facilitate chest compression. Some employ a piston mechanism positioned over the sternum. The LUCAS device, which employs a piston, also includes a suction cup interface with the chest wall to allow active decompression during the recoil phase of the duty cycle. Other devices, namely the ZOLL Autopulse, use a load-distributing band which encircles the chest of the patient. Activation of the device causes a rhythmic shortening and lengthening of the band to compress the chest circumferentially. Early evidence, including animal studies and observational studies in humans suggested that mechanical chest compression devices might be superior to conventional manual chest compressions during cardiac arrest.2 However, there has always been a concern that the devices may cause injury (eg, internal organ trauma) or may introduce dangerous interruptions in chest compressions while they are being deployed during resuscitation attempts. Several clinical trials have been published to explore the effectiveness of mechanical chest compression devices compared with standard manual compressions during cardiac arrest. Our Cochrane systematic review sought to evaluate these clinical trials and determine the relative effectiveness of these two strategies for cardiac arrest.2 We performed a systematic review by searching the following databases: …

The concept that impaired lymphatic flow during the progression of Crohn’s disease, a major form of inflammatory bowel disease, emerged decades ago, but remains unresolved. In Crohn’s disease, tertiary lymphoid organs (TLOs) are associated with collecting lymphatic vessels (CLVs) of the mesentery that govern lymph outflow from the intestine. Whether TLOs affect lymph transport is unknown. In the TNFDARE mouse model of Crohn’s-like ileitis, TLOs formed at valve regions which supported lymphangiogenic outgrowths to the TLOs. Photoconversion approaches to study cell trafficking indicated that TLOs received immune cells traveling from the intestine but scarcely allowed their egress, effectively trapping DCs, B, and T cells. Using adoptive transfer of microbiota-dependent TCR we found reduced overall Tregs differentiation and their presence shifted from the lymph nodes to TLOs, altering intestinal-induced responses. Strikingly, although anti-TNF therapy dampens gut inflammation, TLO are refractory the therapy. Moreover, passage of soluble fluorescent tracer through TLO-rich CLVs was also impeded, indicating transport defects were intrinsic to the CLVs. Indeed, lymph flow diverted at TLO to neighboring CLV branches, where dysfunctional valves allowed lymph return to the gut wall, accompanied by lymph leakage at the TLOs. Culturing lymphatic endothelial cells with TNF demonstrate that the cytokine alone can reduce key genes found in lymphatic valves. These data indicate that TNF disrupts lymphatic valve maintenance pathways, promoting formation of mesenteric TLOs that broadly impair lymph transit of molecules and cells from the intestine, impairing immune surveillance of the mucosal barrier, altering homeostasis.

This paper applies kinematic synthesis theory to obtain the dimensions of a constrained spatial serial chain for a valve mechanism that cleans and closes a soil conditioning port in a tunnel boring machine. The goal is a smooth movement that rotates a cylindrical array of studs into position and then translates it forward to clean and close the port. The movement of the valve is defined by six positions of the revolute-prismatic-revolute (RPR) serial chain. These six positions are used to compute the dimensions of the two spherical spherical (SS) dyads that constrain the RPR chain to obtain a one degree-of-freedom spatial mechanism. An example design of this valve mechanism is provided in detail.

This paper presents a design procedure to achieve a flapping wing mechanism for a micro-air vehicle that coordinates both the wing swing and wing pitch with one actuator. The mechanism combines a planar four-bar linkage with a spatial four-bar linkage attached to the input and output links forming a six-bar linkage. The planar four-bar linkage was designed to control the wing swing trajectory profile and the spatial four-bar linkage was designed to coordinate the pitch of the wing to the swing movement. Tolerance zones were specified around the accuracy points, which were then sampled to generate a number of design candidates. The result was 29 designs that achieve the desired coordination of wing swing and pitch, and a prototype was constructed.

CCCTC-binding factor (CTCF) is an 11 zinc finger DNA-binding domain protein that regulates gene expression by modifying 3D chromatin structure. Human mutations inCTCFcause intellectual disability and autistic features. Knocking outCtcfin mouse embryonic neurons is lethal by neonatal age, but the effects of CTCF deficiency in postnatal neurons are less well studied. We knocked outCtcfpostnatally in glutamatergic forebrain neurons under the control ofCamk2a-Cre. CtcfloxP/loxP;Camk2a-Cre+(CtcfCKO) mice of both sexes were viable and exhibited profound deficits in spatial learning/memory, impaired motor coordination, and decreased sociability by 4 months of age.CtcfCKO mice also had reduced dendritic spine density in the hippocampus and cerebral cortex. Microarray analysis of mRNA fromCtcfCKO mouse hippocampus identified increased transcription of inflammation-related genes linked to microglia. Separate microarray analysis of mRNA isolated specifically fromCtcfCKO mouse hippocampal neurons by ribosomal affinity purification identified upregulation of chemokine signaling genes, suggesting crosstalk between neurons and microglia inCtcfCKO hippocampus. Finally, we found that microglia inCtcfCKO mouse hippocampus had abnormal morphology by Sholl analysis and increased immunostaining for CD68, a marker of microglial activation. Our findings confirm thatCtcfKO in postnatal neurons causes a neurobehavioral phenotype in mice and provide novel evidence that CTCF depletion leads to overexpression of inflammation-related genes and microglial dysfunction.SIGNIFICANCE STATEMENTCCCTC-binding factor (CTCF) is a DNA-binding protein that organizes nuclear chromatin topology. Mutations inCTCFcause intellectual disability and autistic features in humans. CTCF deficiency in embryonic neurons is lethal in mice, but mice with postnatal CTCF depletion are less well studied. We find that mice lackingCtcfinCamk2a-expressing neurons (CtcfCKO mice) have spatial learning/memory deficits, impaired fine motor skills, subtly altered social interactions, and decreased dendritic spine density. We demonstrate thatCtcfCKO mice overexpress inflammation-related genes in the brain and have microglia with abnormal morphology that label positive for CD68, a marker of microglial activation. Our findings suggest that inflammation and dysfunctional neuron–microglia interactions are factors in the pathology of CTCF deficiency.

This paper designs a one degree-of-freedom (1DOF) spatial flapping wing mechanism for a hovering micro-air vehicle by constraining a spatial RRR serial chain using two SS dyads. The desired wing movement defines the dimensions and joint trajectories of the RRR spatial chain. Seven configurations of the chain are selected to define seven precision points that are used to compute SS chains that control the swing and pitch joint angles. The result is a spatial RRR-2SS flapping wing mechanism that transforms the actuator rotation into control of wing swing and pitch necessary for hovering flight of a micro-air vehicle.

This paper presents a design procedure to achieve a flapping wing mechanism for a micro air vehicle that drives both the swing and pitch movement of the wing with one actuator. The mechanism combines a planar four bar linkage with a spatial RSSR attached to the input and output links forming a spatial Stephenson six-bar linkage. Function generation synthesis yields a planar four-bar that controls the wing swing profile. The pitch control is synthesized by inverting the movement of the combined system to isolate and compute the SS chain. In order to ensure the design achieves the specified task precision points, the SS chain was randomized within a prescribed tolerance zone. The result was 29 designs, one of which is presented in detail.

This paper presents a design and manufacturing methodology for a mechanical system that draws trigonometric curves assembled from a series of links connected by gears. We demonstrate this technique using 11 gear-coupled links that trace a butterfly curve. The equation of a butterfly curve is converted to the relative rotations of the links of a coupled serial chain assembled so it operates with one input. We present a procedure to determine the adjustments to the gear ratios and link dimensions necessary for practical manufacture of the mechanism. The results are demonstrated by a working prototype.