258 research outputs found
NMFS: Network Multimedia File System Protocol
We describe an on-going project to develop a Network Multimedia File System (NMFS) protocol. The protocol allows "transparent access of shared files across networks" as Sun's NFS protocol does, but attempts to meet a real-time delivery schedule. NMFS is designed to provide ubiquitous service over networks both designed and not designed to carry multimedia traffic
Pancreatic regenerating protein (regâ… ) and regâ… receptor mRNA are upregulated in rat pancreas after induction of acute pancreatitis
AIM: Pancreatic regenerating protein (regI) stimulates pancreatic regeneration after pancreatectomy and is mitogenic to ductal and β-cells. This suggests that regIand its receptor may play a role in recovery after pancreatic injury. We hypothesized that regIand its receptor are induced in acute pancreatitis. METHODS: Acute pancreatitis was induced in male Wistar rats by retrograde injection of 3% sodium taurocholate into the pancreatic duct. Pancreata and serum were collected 12, 24, and 36 hours after injection and from normal controls (4 rats/group). RegIreceptor mRNA, serum regIprotein, and tissue regIprotein levels were determined by Northern analysis, enzyme-linked immunosorbent assay (ELISA), and Western analysis, respectively. Immunohistochemistry was used to localize changes in regIand its receptor. RESULTS: Serum amylase levels and histology confirmed necrotizing pancreatitis in taurocholate treated rats. There was no statistically significant change in serum regIconcentrations from controls. However, Western blot demonstrated increased tissue levels of regIat 24 and 36 h. This increase was localized primarily to the acinar cells and the ductal cells by immunohistochemistry. Northern blot demonstrated a significant increase in regIreceptor mRNA expression with pancreatitis. Immunohistochemistry localized this increase to the ductal cells, islets, and acinar cells. CONCLUSION: Acute pancreatitis results in increased tissue regIprotein levels localized to the acinar and ductal cells, and a parallel threefold induction of regIreceptor in the ductal cells, islets, and acinar cells. These changes suggest that induction of regIand its receptor may be important for recovery from acute pancreatitis
CARBONIZED STARCH MICROCELLULAR FOAM-CELLULOSE FIBER COMPOSITE STRUCTURES
The production of microporous carbon foams from renewable starch microcellular foam-fiber (SMCF-Fiber) composites is described. Carbon foams are used in applications such as thermal insulation, battery electrodes, filters, fuel cells, and medical devices. SMCF-Fiber compos-ites were created from an aquagel. The water in the aquagel was exchanged with ethanol and then dried and carbonized. Higher amylose content starches and fiber contents of up to 4% improved the processability of the foam. The SMCF structure revealed agglomerates of swollen starch granules connected by a web of starch with pores in the 50-200 nanometer range. Heating the SMCF-fiber in a nitrogen atmosphere to temperatures between 350-700ËšC produced carbon foams with a three-dimensional closed cell foam structure with cell diameters around 50 microns and pore walls around 1-3 microns. The stress versus strain compression data for carbonized samples displayed a linear elastic region and a plateau indicative of brittle crushing, typical of an elastic-brittle foam. The carbon foam products from these renew-able precursors are promising carbon structures with moderate strength and low density
Lymphovascular and perineural invasion as selection criteria for adjuvant therapy in intrahepatic cholangiocarcinoma: a multi-institution analysis
AbstractObjectivesCriteria for the selection of patients for adjuvant chemotherapy in intrahepatic cholangiocarcinoma (IHCC) are lacking. Some authors advocate treating patients with lymph node (LN) involvement; however, nodal assessment is often inadequate or not performed. This study aimed to identify surrogate criteria based on characteristics of the primary tumour.MethodsA total of 58 patients who underwent resection for IHCC between January 2000 and January 2010 at any of three institutions were identified. Primary outcome was overall survival (OS).ResultsMedian OS was 23.0months. Median tumour size was 6.5cm and the median number of lesions was one. Overall, 16% of patients had positive margins, 38% had perineural invasion (PNI), 40% had lymphovascular invasion (LVI) and 22% had LN involvement. A median of two LNs were removed and a median of zero were positive. Lymph nodes were not sampled in 34% of patients. Lymphovascular and perineural invasion were associated with reduced OS [9.6months vs. 32.7months (P= 0.020) and 10.7months vs. 32.7months (P= 0.008), respectively]. Lymph node involvement indicated a trend towards reduced OS (10.7months vs. 30.0months; P= 0.063). The presence of either LVI or PNI in node-negative patients was associated with a reduction in OS similar to that in node-positive patients (12.1months vs. 10.7months; P= 0.541). After accounting for adverse tumour factors, only LVI and PNI remained associated with decreased OS on multivariate analysis (hazard ratio4.07, 95% confidence interval 1.60–10.40; P= 0.003).ConclusionsLymphovascular and perineural invasion are separately associated with a reduction in OS similar to that in patients with LN-positive disease. As nodal dissection is often not performed and the number of nodes retrieved is frequently inadequate, these tumour-specific factors should be considered as criteria for selection for adjuvant chemotherapy
Robust Single-view Cone-beam X-ray Pose Estimation with Neural Tuned Tomography (NeTT) and Masked Neural Radiance Fields (mNeRF)
Many tasks performed in image-guided, mini-invasive, medical procedures can
be cast as pose estimation problems, where an X-ray projection is utilized to
reach a target in 3D space. Expanding on recent advances in the differentiable
rendering of optically reflective materials, we introduce new methods for pose
estimation of radiolucent objects using X-ray projections, and we demonstrate
the critical role of optimal view synthesis in performing this task. We first
develop an algorithm (DiffDRR) that efficiently computes Digitally
Reconstructed Radiographs (DRRs) and leverages automatic differentiation within
TensorFlow. Pose estimation is performed by iterative gradient descent using a
loss function that quantifies the similarity of the DRR synthesized from a
randomly initialized pose and the true fluoroscopic image at the target pose.
We propose two novel methods for high-fidelity view synthesis, Neural Tuned
Tomography (NeTT) and masked Neural Radiance Fields (mNeRF). Both methods rely
on classic Cone-Beam Computerized Tomography (CBCT); NeTT directly optimizes
the CBCT densities, while the non-zero values of mNeRF are constrained by a 3D
mask of the anatomic region segmented from CBCT. We demonstrate that both NeTT
and mNeRF distinctly improve pose estimation within our framework. By defining
a successful pose estimate to be a 3D angle error of less than 3 deg, we find
that NeTT and mNeRF can achieve similar results, both with overall success
rates more than 93%. However, the computational cost of NeTT is significantly
lower than mNeRF in both training and pose estimation. Furthermore, we show
that a NeTT trained for a single subject can generalize to synthesize
high-fidelity DRRs and ensure robust pose estimations for all other subjects.
Therefore, we suggest that NeTT is an attractive option for robust pose
estimation using fluoroscopic projections
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Clinical features of brain metastasis from salivary gland tumors
Salivary gland tumors comprise a group of 24 tumor subtypes with a wide range of clinical behaviors and propensities for metastasis. Several prognostic factors have been identified that help predict the development of systemic metastases, most commonly to the lung, liver, or bone. Metastases to the brain are rare. To better understand the behavior of salivary gland tumors that metastasise to the brain, we performed a retrospective cohort analysis on a series of patients to highlight features of their medical and surgical management. From 2007 to 2011, a database of 4117 elective craniotomies were queried at a single institution to identify patients surgically treated for salivary gland metastases to the brain. Three patients were identified. Histologic subtypes included salivary duct carcinoma, poorly differentiated carcinoma, and papillary mucinous adenocarcinoma. They had all undergone previous treatment for their primary malignancy. The mean time to intracranial metastasis was 48 months from initial diagnosis (range, 14–91 months). Treatment for intracranial metastases included surgical resection, whole brain radiation, stereotactic radiosurgery, and chemotherapy. Intracranial metastases from salivary gland tumors are rare, present years after diagnosis of the primary tumor, and are treatable with multimodality therapy
Pharmacological targeting of the mitochondrial calcium-dependent potassium channel KCa3.1 triggers cell death and reduces tumor growth and metastasis in vivo
Ion channels are non-conventional, druggable oncological targets. The intermediate-conductance calcium-dependent potassium channel (K(Ca)3.1) is highly expressed in the plasma membrane and in the inner mitochondrial membrane (mitoK(Ca)3.1) of various cancer cell lines. The role mitoK(Ca)3.1 plays in cancer cells is still undefined. Here we report the synthesis and characterization of two mitochondria-targeted novel derivatives of a high-affinity K(Ca)3.1 antagonist, TRAM-34, which retain the ability to block channel activity. The effects of these drugs were tested in melanoma, pancreatic ductal adenocarcinoma and breast cancer lines, as well as in vivo in two orthotopic models. We show that the mitochondria-targeted TRAM-34 derivatives induce release of mitochondrial reactive oxygen species, rapid depolarization of the mitochondrial membrane, fragmentation of the mitochondrial network. They trigger cancer cell death with an EC50 in the mu M range, depending on channel expression. In contrast, inhibition of the plasma membrane K(Ca)3.1 by membrane-impermeant Maurotoxin is without effect, indicating a specific role of mitoK(Ca)3.1 in determining cell fate. At sub-lethal concentrations, pharmacological targeting of mitoK(Ca)3.1 significantly reduced cancer cell migration by enhancing production of mitochondrial reactive oxygen species and nuclear factor-kappa B (NF-kappa B) activation, and by downregulating expression of Bcl-2 Nineteen kD-Interacting Protein (BNIP-3) and of Rho GTPase CDC-42. This signaling cascade finally leads to cytoskeletal reorganization and impaired migration. Overexpression of BNIP-3 or pharmacological modulation of NF-kappa B and CDC-42 prevented the migration-reducing effect of mitoTRAM-34. In orthotopic models of melanoma and pancreatic ductal adenocarcinoma, the tumors at sacrifice were 60% smaller in treated versus untreated animals. Metastasis of melanoma cells to lymph nodes was also drastically reduced. No signs of toxicity were observed. In summary, our results identify mitochondrial K(Ca)3.1 as an unexpected player in cancer cell migration and show that its pharmacological targeting is efficient against both tumor growth and metastatic spread in vivo
A National Multi-Institutional Analysis of Predictors of Surgical Site Complications and Unplanned Reoperation after Paramedian Forehead Flap Reconstruction
Background: Although postoperative complications of paramedian forehead flap (PMFF) are generally low, surgical site complications and unplanned reoperation can still occur. Recent literature suggests infection to be the most common complication following PMFF reconstruction. This study sought to determine the patient and preoperative factors associated with surgical site complications and unplanned reoperations at a national level.
Methods: Patients who underwent PMFF reconstruction from the ACS-NSQIP 2007 - 2019 database were analyzed to determine composite surgical site morbidity and unplanned return to the operating room. Patient and operative factors were also analyzed to assess independent risk factors for surgical site morbidity and unplanned reoperation in the first 30 postoperative days.
Results: A total of 1,592 PMFF were analyzed between 2007 and 2019. Of these, 2.7% (43/1592) developed a composite surgical site complication in the first 30 postoperative days. Risk factors for composite surgical site complication included \u3e10% weight loss in the previous 6 months (
Conclusion: Significant weight loss, disseminated cancer, prolonged operation time, low preoperative albumin, and hematocrit are associated with higher PMFF composite surgical site complications. Higher ASA and class 4 wound status are associated with an increased risk of unplanned reoperation
Neutrino propagation in the Earth and emerging charged leptons with
Ultra-high-energy neutrinos serve as messengers of some of the highest energy
astrophysical environments. Given that neutrinos are neutral and only interact
via weak interactions, neutrinos can emerge from sources, traverse astronomical
distances, and point back to their origins. Their weak interactions require
large target volumes for neutrino detection. Using the Earth as a neutrino
converter, terrestrial, sub-orbital, and satellite-based instruments are able
to detect signals of neutrino-induced extensive air showers. In this paper, we
describe the software code that simulates tau neutrino and
muon neutrino interactions in the Earth and predicts the spectrum of the
-lepton and muons that emerge. The outputs are lookup
tables of charged lepton exit probabilities and energies that can be used
directly or as inputs to the code designed to simulate
optical and radio signals from extensive air showers induced by the emerging
charged leptons. We describe the inputs to the code, demonstrate its
flexibility and show selected results for -lepton and muon exit
probabilities and energy distributions. The code is open
source, available on github.Comment: 42 pages, 21 figures, code available at
https://github.com/NuSpaceSim/nupypro
FOLFIRINOX or Gemcitabine-based Chemotherapy for Borderline Resectable and Locally Advanced Pancreatic Cancer: A Multi-institutional, Patient-Level, Meta-analysis and Systematic Review
BACKGROUND
Pancreatic cancer often presents as locally advanced (LAPC) or borderline resectable (BRPC). Neoadjuvant systemic therapy is recommended as initial treatment. It is currently unclear what chemotherapy should be preferred for patients with BRPC or LAPC.
METHODS
We performed a systematic review and multi-institutional meta-analysis of patient-level data regarding the use of initial systemic therapy for BRPC and LAPC. Outcomes were reported separately for tumor entity and by chemotherapy regimen including FOLFIRINOX (FIO) or gemcitabine-based.
RESULTS
A total of 23 studies comprising 2930 patients were analyzed for overall survival (OS) calculated from the beginning of systemic treatment. OS for patients with BRPC was 22.0 months with FIO, 16.9 months with gemcitabine/nab-paclitaxel (Gem/nab), 21.6 months with gemcitabine/cisplatin or oxaliplatin or docetaxel or capecitabine (GemX), and 10 months with gemcitabine monotherapy (Gem-mono) (p < 0.0001). In patients with LAPC, OS also was higher with FIO (17.1 months) compared with Gem/nab (12.5 months), GemX (12.3 months), and Gem-mono (9.4 months; p < 0.0001). This difference was driven by the patients who did not undergo surgery, where FIO was superior to other regimens. The resection rates for patients with BRPC were 0.55 for gemcitabine-based chemotherapy and 0.53 with FIO. In patients with LAPC, resection rates were 0.19 with Gemcitabine and 0.28 with FIO. In resected patients, OS for patients with BRPC was 32.9 months with FIO and not different compared to Gem/nab, (28.6 months, p = 0.285), GemX (38.8 months, p = 0.1), or Gem-mono (23.1 months, p = 0.083). A similar trend was observed in resected patients converted from LAPC.
CONCLUSIONS
In patients with BRPC or LAPC, primary treatment with FOLFIRINOX compared with Gemcitabine-based chemotherapy appears to provide a survival benefit for patients that are ultimately unresectable. For patients that undergo surgical resection, outcomes are similar between GEM+ and FOLFIRINOX when delivered in the neoadjuvant setting
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