BACKGROUND: Intracerebral hemorrhage is the least treatable form of stroke and is associated with high mortality.Among patients who undergo computed tomograph y (CT) within three hours after the onset of intracerebral...BACKGROUND: Intracerebral hemorrhage is the least treatable form of stroke and is associated with high mortality.Among patients who undergo computed tomograph y (CT) within three hours after the onset of intracerebral hemorrhage, one third have an increase in the volume of the hematoma related to subsequent bleeding. We sought to determine whether recombinant activated factor VII (rFVIIa) can red uce hematoma growth after intracerebral hemorrhage. METHODS: We randomly assigne d 399 patients with intracerebral hemorrhage diagnosed by CT within three hours after onset to receive placebo (96 patients) or 40 μg of rFVIIa per kilogram of body weight (108 patients), 80 μg per kilogram (92 patients), or 160 μg per k ilogram (103 patients) within one hour after the baseline scan. The primary outc ome measure was the percent change in the volume of the intracerebral hemorrhage at 24 hours. Clinical outcomes were assessed at 90 days. RESULTS: Hematoma volu me increased more in the placebo group than in the rFVIIa groups. The mean incre ase was 29 percent in the placebo group, as compared with 16 percent, 14 percent , and 11 percent in the groups given 40 μg, 80 μg, and 160 μg of rFVIIa per k ilogram, respectively (P=0.01 for the comparison of the three rFVIIa groups with the placebo group). Growth in the volume of intracerebral hemorrhage was reduce d by 3.3 ml, 4.5 ml, and 5.8 ml in the three treatment groups, as compared with that in the placebo group (P=0.01). Sixty-nine percent of placebo-treated pati ents died or were severely disabled (as defined by a modified Rankin Scale score of 4 to 6), as compared with 55 percent, 49 percent, and 54 percent of the pati ents who were given 40, 80, and 160 μg of rFVIIa, respectively (P=0.004 for the comparison of the three rFVIIa groups with the placebo group). Mortality at 90 days was 29 percent for patients who received placebo, as compared with 18 perce nt in the three rFVIIa groups combined (P=0.02). Serious thromboembolic adverse events, mainly myocardial or cerebral i展开更多
Alimentary tract duplications are rare congenital lesions normally diagnosed in newborns and children that can occur anywhere from the mouth to the anus and have a reported incidence of approximately 1 in 4500 life bi...Alimentary tract duplications are rare congenital lesions normally diagnosed in newborns and children that can occur anywhere from the mouth to the anus and have a reported incidence of approximately 1 in 4500 life births. Symptoms and clinical presentation vary greatly. The presentation varies according to age and location. The treatment finally is surgical; total resection when possible should be the aim of the intervention. In pediatric surgery minimally invasive surgical procedures became more and more important over the last decades. In consequence the operative procedure on alimentary tract duplications changed in this manner. We review on case reports and clinical reports on minimally invasive surgery in the treatment of alimentary tract duplications, determine the importance of minimally invasive techniques in the treatment of this rare entity and rule out that further studies in the field should be performed.展开更多
Retrofitting older vehicles with diesel particulate filter（DPF） is a cost-effective measure to quickly and efficiently reduce particulate matter emissions. This study experimentally analyzes real-world performance o...Retrofitting older vehicles with diesel particulate filter（DPF） is a cost-effective measure to quickly and efficiently reduce particulate matter emissions. This study experimentally analyzes real-world performance of buses retrofitted with CRT DPFs. 18 in-use Euro III technology urban and intercity buses were investigated for a period of 12 months. The influence of the DPF and of the vehicle natural aging on buses fuel economy are analyzed and discussed. While the effect of natural deterioration is about 1.2%–1.3%, DPF contribution to fuel economy penalty is found to be 0.6% to 1.8%, depending on the bus type. DPF filtration efficiency is analyzed throughout the study and found to be in average 96% in the size range of 23–560 nm. Four different load and non-load engine operating modes are investigated on their appropriateness for roadworthiness tests. High idle is found to be the most suitable regime for PN diagnostics considering particle number filtration efficiency.展开更多
Clear cell hepatocellular carcinoma(CCHCC)has hitherto been considered an uncommon, highly differentiated variant of hepatocellular carcinoma(HCC) with a relatively favorable prognosis. CCHCC is composed of mixtures o...Clear cell hepatocellular carcinoma(CCHCC)has hitherto been considered an uncommon, highly differentiated variant of hepatocellular carcinoma(HCC) with a relatively favorable prognosis. CCHCC is composed of mixtures of clear and/or acidophilic ground glass hepatocytes with excessive glycogen and/or fat and shares histology, clinical features and etiology with common HCCs. Studies in animal models of chemical, hormonal and viral hepatocarcinogenesis and observations in patients with chronic liver diseases prone to develop HCC have shown that the majority of HCCs are preceded by, or associated with, focal or diffuse excessive storage of glycogen(glycogenosis) which later may be replaced by fat(lipidosis/steatosis). In ground glass cells, the glycogenosis is accompanied by proliferation of the smooth endoplasmic reticulum, which is closely related to glycogen particles and frequently harbors the hepatitis B surface antigen(HBs Ag).From the findings in animal models a sequence of changes has been established, commencing with preneoplastic glycogenotic liver lesions, often containing ground glass cells, and progressing to glycogen-poor neoplasms via various intermediate stages, including glycogenotic/lipidotic clear cell foci, clear cell hepatocellular adenomas(CCHCA) rich in glycogen and/or fat, and CCHCC. A similar process seems to take place in humans, with clear cells frequently persisting in CCHCC and steatohepatitic HCC, which presumably represent intermediate stages in the development rather than particular variants of HCC. During the progression of the preneoplastic lesions,the clear and ground glass cells transform into cells characteristic of common HCC. The sequential cellular changes are associated with metabolic aberrations, which start with an activation of the insulin signaling cascade resulting in preneoplastic hepatic glycogenosis. The molecular and metabolic changes underlying the glycogenosis/lipidosis are apparently responsible for the dramatic metabolic shift from gluconeogenesis to the pentose ph展开更多
Based on a thorough theory of the Artin transfer homomorphism from a group G to the abelianization of a subgroup of finite index , and its connection with the permutation representation and the monomial representation...Based on a thorough theory of the Artin transfer homomorphism from a group G to the abelianization of a subgroup of finite index , and its connection with the permutation representation and the monomial representation of G, the Artin pattern , which consists of families , resp. , of transfer targets, resp. transfer kernels, is defined for the vertices of any descendant tree T of finite p-groups. It is endowed with partial order relations and , which are compatible with the parent-descendant relation of the edges of the tree T. The partial order enables termination criteria for the p-group generation algorithm which can be used for searching and identifying a finite p-group G, whose Artin pattern is known completely or at least partially, by constructing the descendant tree with the abelianization of G as its root. An appendix summarizes details concerning induced homomorphisms between quotient groups, which play a crucial role in establishing the natural partial order on Artin patterns and explaining the stabilization, resp. polarization, of their components in descendant trees T of finite p-groups.展开更多
Despite the maturity of ensemble numerical weather prediction(NWP),the resulting forecasts are still,more often than not,under-dispersed.As such,forecast calibration tools have become popular.Among those tools,quantil...Despite the maturity of ensemble numerical weather prediction(NWP),the resulting forecasts are still,more often than not,under-dispersed.As such,forecast calibration tools have become popular.Among those tools,quantile regression(QR)is highly competitive in terms of both flexibility and predictive performance.Nevertheless,a long-standing problem of QR is quantile crossing,which greatly limits the interpretability of QR-calibrated forecasts.On this point,this study proposes a non-crossing quantile regression neural network(NCQRNN),for calibrating ensemble NWP forecasts into a set of reliable quantile forecasts without crossing.The overarching design principle of NCQRNN is to add on top of the conventional QRNN structure another hidden layer,which imposes a non-decreasing mapping between the combined output from nodes of the last hidden layer to the nodes of the output layer,through a triangular weight matrix with positive entries.The empirical part of the work considers a solar irradiance case study,in which four years of ensemble irradiance forecasts at seven locations,issued by the European Centre for Medium-Range Weather Forecasts,are calibrated via NCQRNN,as well as via an eclectic mix of benchmarking models,ranging from the naïve climatology to the state-of-the-art deep-learning and other non-crossing models.Formal and stringent forecast verification suggests that the forecasts post-processed via NCQRNN attain the maximum sharpness subject to calibration,amongst all competitors.Furthermore,the proposed conception to resolve quantile crossing is remarkably simple yet general,and thus has broad applicability as it can be integrated with many shallow-and deep-learning-based neural networks.展开更多
BACKGROUND:We investigated whether the use of a specially designed visual estimation tool may improve accuracy in quantifying blood volumes related to surface spreading.METHODS:A prospective,paired-control,single-blin...BACKGROUND:We investigated whether the use of a specially designed visual estimation tool may improve accuracy in quantifying blood volumes related to surface spreading.METHODS:A prospective,paired-control,single-blinded experimental study was performed at a medical university.Anesthesiologists and emergency medical personnel estimated various blood volumes on surfaces with varying absorptivity(carpet,towel,polyvinyl chloride,wooden fl ooring)in an experimental setting.We assessed the sensitivity of training blood volume quantifi cation using a self-designed visual estimation tool by comparing the accuracy of visual blood volume estimations before and after practical training with the tool.RESULTS:A total of 352 estimations by 44 participants were evaluated.Accurate estimations improved significantly from pre-training to post-training(P<0.05).The sensitivity of blood volume quantifi cation was 33.0%after training with the visual estimation tool.Estimations did not depend on age,profession,gender or years of the estimator’s professional experience.CONCLUSIONS:Training with a visual estimation tool by professional rescuers can improve the estimation accuracy of blood volumes spread on surfaces with varying absorptivity.展开更多
AIM： To describe retinal findings of various imaging modalities in acute retinal ischemia. METHODS： Fluorescein angiography（FA）, spectral domain optical coherence tomography（SD-OCT）, OCTangiography（OCT-A） and ...AIM： To describe retinal findings of various imaging modalities in acute retinal ischemia. METHODS： Fluorescein angiography（FA）, spectral domain optical coherence tomography（SD-OCT）, OCTangiography（OCT-A） and fundus autofluorescence（FAF） images of 13 patients（mean age 64y, range 28-86y） with acute retinal ischemia were evaluated. Six suffered from branch arterial occlusion, 2 had a central retinal artery occlusion, 2 had a combined arteriovenous occlusions, 1 patient had a retrobulbar arterial compression by an orbital haemangioma and 2 patients showed an ocular ischemic syndrome.RESULTS： All patients showed increased reflectivity and thickening of the ischemic retinal tissue. In 10 out of 13 patients SD-OCT revealed an additional highly reflective band located within or above the outer plexiform layer. Morphological characteristics were a decreasing intensity with distance from the fovea, partially segmental occurrence and manifestation limited in time. OCT-A showed a loss of flow signal in the superficial and deep capillary plexus at the affected areas. Reduced flow signal was detected underneath the regions with retinal edema. FAF showed areas of altered signal intensity at the posterior pole. The regions of decreased FAF signal corresponded to peri-venous regions. CONCLUSION： Multimodal imaging modalities in retinal ischemia yield characteristic findings and valuable diagnostic information. Conventional OCT identifies hyperreflectivity and thickening and a mid-retinal hyperreflective band is frequently observed. OCT-A examination reveals demarcation of the ischemic retinal area on the vascular level. FAF shows decreased fluorescence signal in areas of retinal edema often corresponding to peri-venous regions.展开更多
In recent years,multi-photon 3D laser printing has become a widely used tool for the fabrication of micro-and nanostructures for a large variety of applications.Typically,thorough sample characterisation is key for an...In recent years,multi-photon 3D laser printing has become a widely used tool for the fabrication of micro-and nanostructures for a large variety of applications.Typically,thorough sample characterisation is key for an efficient optimisation of the printing process.To date,three-dimensional microscopic inspection has usually been carried out on finished 3D printed microstructures,that is,using ex-situ approaches.In contrast,in-situ 3D characterization tools are desirable for quickly assessing the quality and properties of 3D printed microstructures.Along these lines,we present and characterise a Fourier-domain optical coherence tomography(FD-OCT)system that can be readily integrated into an existing 3D laser lithography setup.We demonstrate its capabilities by examining different 3D printed polymer microstructures immersed in a liquid photoresist.In such samples,local reflectivity arises from the(refractive-index)contrasts between the polymerised and non-polymerised regions.Thus,the refractive index of the printed material can be extracted.Furthermore,we demonstrate that the reflectivity of polymer-monomer transitions exhibits time-dependent behaviour after printing.Supported by transfer-matrix calculations,we explain this effect in terms of the time-dependent graded-index transition originating from monomer diffusion into the polymer matrix.Finally,we show exemplary 3D reconstructions of printed structures that can be readily compared with 3D computer designs.展开更多
文摘BACKGROUND: Intracerebral hemorrhage is the least treatable form of stroke and is associated with high mortality.Among patients who undergo computed tomograph y (CT) within three hours after the onset of intracerebral hemorrhage, one third have an increase in the volume of the hematoma related to subsequent bleeding. We sought to determine whether recombinant activated factor VII (rFVIIa) can red uce hematoma growth after intracerebral hemorrhage. METHODS: We randomly assigne d 399 patients with intracerebral hemorrhage diagnosed by CT within three hours after onset to receive placebo (96 patients) or 40 μg of rFVIIa per kilogram of body weight (108 patients), 80 μg per kilogram (92 patients), or 160 μg per k ilogram (103 patients) within one hour after the baseline scan. The primary outc ome measure was the percent change in the volume of the intracerebral hemorrhage at 24 hours. Clinical outcomes were assessed at 90 days. RESULTS: Hematoma volu me increased more in the placebo group than in the rFVIIa groups. The mean incre ase was 29 percent in the placebo group, as compared with 16 percent, 14 percent , and 11 percent in the groups given 40 μg, 80 μg, and 160 μg of rFVIIa per k ilogram, respectively (P=0.01 for the comparison of the three rFVIIa groups with the placebo group). Growth in the volume of intracerebral hemorrhage was reduce d by 3.3 ml, 4.5 ml, and 5.8 ml in the three treatment groups, as compared with that in the placebo group (P=0.01). Sixty-nine percent of placebo-treated pati ents died or were severely disabled (as defined by a modified Rankin Scale score of 4 to 6), as compared with 55 percent, 49 percent, and 54 percent of the pati ents who were given 40, 80, and 160 μg of rFVIIa, respectively (P=0.004 for the comparison of the three rFVIIa groups with the placebo group). Mortality at 90 days was 29 percent for patients who received placebo, as compared with 18 perce nt in the three rFVIIa groups combined (P=0.02). Serious thromboembolic adverse events, mainly myocardial or cerebral i
文摘Alimentary tract duplications are rare congenital lesions normally diagnosed in newborns and children that can occur anywhere from the mouth to the anus and have a reported incidence of approximately 1 in 4500 life births. Symptoms and clinical presentation vary greatly. The presentation varies according to age and location. The treatment finally is surgical; total resection when possible should be the aim of the intervention. In pediatric surgery minimally invasive surgical procedures became more and more important over the last decades. In consequence the operative procedure on alimentary tract duplications changed in this manner. We review on case reports and clinical reports on minimally invasive surgery in the treatment of alimentary tract duplications, determine the importance of minimally invasive techniques in the treatment of this rare entity and rule out that further studies in the field should be performed.
基金financially supported by Egged Israel Transport Cooperative Society Ltd.
文摘Retrofitting older vehicles with diesel particulate filter（DPF） is a cost-effective measure to quickly and efficiently reduce particulate matter emissions. This study experimentally analyzes real-world performance of buses retrofitted with CRT DPFs. 18 in-use Euro III technology urban and intercity buses were investigated for a period of 12 months. The influence of the DPF and of the vehicle natural aging on buses fuel economy are analyzed and discussed. While the effect of natural deterioration is about 1.2%–1.3%, DPF contribution to fuel economy penalty is found to be 0.6% to 1.8%, depending on the bus type. DPF filtration efficiency is analyzed throughout the study and found to be in average 96% in the size range of 23–560 nm. Four different load and non-load engine operating modes are investigated on their appropriateness for roadworthiness tests. High idle is found to be the most suitable regime for PN diagnostics considering particle number filtration efficiency.
基金partly supported by a grant from the Deutsche Forschungsgemeinschaft(RI2695/1-1)
文摘Clear cell hepatocellular carcinoma(CCHCC)has hitherto been considered an uncommon, highly differentiated variant of hepatocellular carcinoma(HCC) with a relatively favorable prognosis. CCHCC is composed of mixtures of clear and/or acidophilic ground glass hepatocytes with excessive glycogen and/or fat and shares histology, clinical features and etiology with common HCCs. Studies in animal models of chemical, hormonal and viral hepatocarcinogenesis and observations in patients with chronic liver diseases prone to develop HCC have shown that the majority of HCCs are preceded by, or associated with, focal or diffuse excessive storage of glycogen(glycogenosis) which later may be replaced by fat(lipidosis/steatosis). In ground glass cells, the glycogenosis is accompanied by proliferation of the smooth endoplasmic reticulum, which is closely related to glycogen particles and frequently harbors the hepatitis B surface antigen(HBs Ag).From the findings in animal models a sequence of changes has been established, commencing with preneoplastic glycogenotic liver lesions, often containing ground glass cells, and progressing to glycogen-poor neoplasms via various intermediate stages, including glycogenotic/lipidotic clear cell foci, clear cell hepatocellular adenomas(CCHCA) rich in glycogen and/or fat, and CCHCC. A similar process seems to take place in humans, with clear cells frequently persisting in CCHCC and steatohepatitic HCC, which presumably represent intermediate stages in the development rather than particular variants of HCC. During the progression of the preneoplastic lesions,the clear and ground glass cells transform into cells characteristic of common HCC. The sequential cellular changes are associated with metabolic aberrations, which start with an activation of the insulin signaling cascade resulting in preneoplastic hepatic glycogenosis. The molecular and metabolic changes underlying the glycogenosis/lipidosis are apparently responsible for the dramatic metabolic shift from gluconeogenesis to the pentose ph
文摘Based on a thorough theory of the Artin transfer homomorphism from a group G to the abelianization of a subgroup of finite index , and its connection with the permutation representation and the monomial representation of G, the Artin pattern , which consists of families , resp. , of transfer targets, resp. transfer kernels, is defined for the vertices of any descendant tree T of finite p-groups. It is endowed with partial order relations and , which are compatible with the parent-descendant relation of the edges of the tree T. The partial order enables termination criteria for the p-group generation algorithm which can be used for searching and identifying a finite p-group G, whose Artin pattern is known completely or at least partially, by constructing the descendant tree with the abelianization of G as its root. An appendix summarizes details concerning induced homomorphisms between quotient groups, which play a crucial role in establishing the natural partial order on Artin patterns and explaining the stabilization, resp. polarization, of their components in descendant trees T of finite p-groups.
基金supported by the National Natural Science Foundation of China (Project No.42375192)the China Meteorological Administration Climate Change Special Program (CMA-CCSP+1 种基金Project No.QBZ202315)support by the Vector Stiftung through the Young Investigator Group"Artificial Intelligence for Probabilistic Weather Forecasting."
文摘Despite the maturity of ensemble numerical weather prediction(NWP),the resulting forecasts are still,more often than not,under-dispersed.As such,forecast calibration tools have become popular.Among those tools,quantile regression(QR)is highly competitive in terms of both flexibility and predictive performance.Nevertheless,a long-standing problem of QR is quantile crossing,which greatly limits the interpretability of QR-calibrated forecasts.On this point,this study proposes a non-crossing quantile regression neural network(NCQRNN),for calibrating ensemble NWP forecasts into a set of reliable quantile forecasts without crossing.The overarching design principle of NCQRNN is to add on top of the conventional QRNN structure another hidden layer,which imposes a non-decreasing mapping between the combined output from nodes of the last hidden layer to the nodes of the output layer,through a triangular weight matrix with positive entries.The empirical part of the work considers a solar irradiance case study,in which four years of ensemble irradiance forecasts at seven locations,issued by the European Centre for Medium-Range Weather Forecasts,are calibrated via NCQRNN,as well as via an eclectic mix of benchmarking models,ranging from the naïve climatology to the state-of-the-art deep-learning and other non-crossing models.Formal and stringent forecast verification suggests that the forecasts post-processed via NCQRNN attain the maximum sharpness subject to calibration,amongst all competitors.Furthermore,the proposed conception to resolve quantile crossing is remarkably simple yet general,and thus has broad applicability as it can be integrated with many shallow-and deep-learning-based neural networks.
文摘BACKGROUND:We investigated whether the use of a specially designed visual estimation tool may improve accuracy in quantifying blood volumes related to surface spreading.METHODS:A prospective,paired-control,single-blinded experimental study was performed at a medical university.Anesthesiologists and emergency medical personnel estimated various blood volumes on surfaces with varying absorptivity(carpet,towel,polyvinyl chloride,wooden fl ooring)in an experimental setting.We assessed the sensitivity of training blood volume quantifi cation using a self-designed visual estimation tool by comparing the accuracy of visual blood volume estimations before and after practical training with the tool.RESULTS:A total of 352 estimations by 44 participants were evaluated.Accurate estimations improved significantly from pre-training to post-training(P<0.05).The sensitivity of blood volume quantifi cation was 33.0%after training with the visual estimation tool.Estimations did not depend on age,profession,gender or years of the estimator’s professional experience.CONCLUSIONS:Training with a visual estimation tool by professional rescuers can improve the estimation accuracy of blood volumes spread on surfaces with varying absorptivity.
文摘AIM： To describe retinal findings of various imaging modalities in acute retinal ischemia. METHODS： Fluorescein angiography（FA）, spectral domain optical coherence tomography（SD-OCT）, OCTangiography（OCT-A） and fundus autofluorescence（FAF） images of 13 patients（mean age 64y, range 28-86y） with acute retinal ischemia were evaluated. Six suffered from branch arterial occlusion, 2 had a central retinal artery occlusion, 2 had a combined arteriovenous occlusions, 1 patient had a retrobulbar arterial compression by an orbital haemangioma and 2 patients showed an ocular ischemic syndrome.RESULTS： All patients showed increased reflectivity and thickening of the ischemic retinal tissue. In 10 out of 13 patients SD-OCT revealed an additional highly reflective band located within or above the outer plexiform layer. Morphological characteristics were a decreasing intensity with distance from the fovea, partially segmental occurrence and manifestation limited in time. OCT-A showed a loss of flow signal in the superficial and deep capillary plexus at the affected areas. Reduced flow signal was detected underneath the regions with retinal edema. FAF showed areas of altered signal intensity at the posterior pole. The regions of decreased FAF signal corresponded to peri-venous regions. CONCLUSION： Multimodal imaging modalities in retinal ischemia yield characteristic findings and valuable diagnostic information. Conventional OCT identifies hyperreflectivity and thickening and a mid-retinal hyperreflective band is frequently observed. OCT-A examination reveals demarcation of the ischemic retinal area on the vascular level. FAF shows decreased fluorescence signal in areas of retinal edema often corresponding to peri-venous regions.
基金This work was funded by the Deutsche Forschungsgemeinschaft(DFG,German Research Foundation)under Germany’s Excellence Strategy 2082/1-390761711(Excellence Cluster“3D Matter Made to Order”).
文摘In recent years,multi-photon 3D laser printing has become a widely used tool for the fabrication of micro-and nanostructures for a large variety of applications.Typically,thorough sample characterisation is key for an efficient optimisation of the printing process.To date,three-dimensional microscopic inspection has usually been carried out on finished 3D printed microstructures,that is,using ex-situ approaches.In contrast,in-situ 3D characterization tools are desirable for quickly assessing the quality and properties of 3D printed microstructures.Along these lines,we present and characterise a Fourier-domain optical coherence tomography(FD-OCT)system that can be readily integrated into an existing 3D laser lithography setup.We demonstrate its capabilities by examining different 3D printed polymer microstructures immersed in a liquid photoresist.In such samples,local reflectivity arises from the(refractive-index)contrasts between the polymerised and non-polymerised regions.Thus,the refractive index of the printed material can be extracted.Furthermore,we demonstrate that the reflectivity of polymer-monomer transitions exhibits time-dependent behaviour after printing.Supported by transfer-matrix calculations,we explain this effect in terms of the time-dependent graded-index transition originating from monomer diffusion into the polymer matrix.Finally,we show exemplary 3D reconstructions of printed structures that can be readily compared with 3D computer designs.
