Experimental Limits on Solar Reflected Dark Matter with a New Approach on Accelerated-Dark-Matter-Electron Analysis in Semiconductors

Recently a dark matter-electron (DM-electron) paradigm has drawn much attention. Models beyond the standard halo model describing DM accelerated by high energy celestial bodies are under intense examination as well. In this Letter, a velocity components analysis (VCA) method dedicated to swift analysis of accelerated DM-electron interactions via semiconductor detectors is proposed and the first HPGe detector-based accelerated DM-electron analysis is realized. Utilizing the method, the first germanium based constraint on sub-GeV solar reflected DM-electron interaction is presented with the 205.4  kg·day dataset from the CDEX-10 experiment. In the heavy mediator scenario, our result excels in the mass range of 5-15  keV/c^{2}, achieving a 3 orders of magnitude improvement comparing with previous semiconductor experiments. In the light mediator scenario, the strongest laboratory constraint for DM lighter than 0.1  MeV/c^{2} is presented. The result proves the feasibility and demonstrates the vast potential of the VCA technique in future accelerated DM-electron analyses with semiconductor detectors.

Modeling the charge collection efficiency in the Li-diffused inactive layer of P-type high purity germanium detector

A model of the Li-diffused inactive layer in P-type high purity germanium detectors is built to describe the transportation of charge carriers and calculate the charge collection efficiency therein. The model is applied to calculate charge collection efficiency of a P-type point-contact germanium detector used in rare event physics experiments and validated in another P-type semi-planar germanium detector. The calculated charge collection efficiency curves are well consistent with measurements for both detectors. Effects of the Li doping processes on the charge collection efficiency are discussed based on the model. This model can be easily extended to other P-type germanium detectors, for instance, the P-type broad-energy Ge detector, and the P-type inverted-coaxial point-contact detector.

[Advances in recurrence risk assessment of gastrointestinal stromal tumor]

Identification of prognosis-related risk factors and accurate assessment of risk stratification in patients with gastrointestinal stromal tumor (GIST) is of great significance not only for establishing a reliable prognostic model and developing a follow-up plan but also for selecting potential populations benefiting from neoadjuvant therapies. Although several risk stratification models have been established, it is still challenging to accurately assess patients' risk of recurrence, and the performance of these prediction models still needs to be improved. This review focused on the latest studies in recurrence risk assessment for GIST patients, and summarized potential predictive markers and recurrence risk models related to tumor-related characteristic parameters, novel laboratory examinations, radiological imaging signatures and molecular pathological features, which could provide a reference for accurate risk stratification and individualized targeted therapies for GIST patients.

Constraints on Sub-GeV Dark Matter-Electron Scattering from the CDEX-10 Experiment

We present improved germanium-based constraints on sub-GeV dark matter via dark matter-electron (χ-e) scattering using the 205.4  kg·day dataset from the CDEX-10 experiment. Using a novel calculation technique, we attain predicted χ-e scattering spectra observable in high-purity germanium detectors. In the heavy mediator scenario, our results achieve 3 orders of magnitude of improvement for m_{χ} larger than 80  MeV/c^{2} compared to previous germanium-based χ-e results. We also present the most stringent χ-e cross-section limit to date among experiments using solid-state detectors for m_{χ} larger than 90  MeV/c^{2} with heavy mediators and m_{χ} larger than 100  MeV/c^{2} with electric dipole coupling. The result proves the feasibility and demonstrates the vast potential of a new χ-e detection method with high-purity germanium detectors in ultralow radioactive background.

Exotic Dark Matter Search with the CDEX-10 Experiment at China's Jinping Underground Laboratory

A search for exotic dark matter (DM) in the sub-GeV mass range has been conducted using 205 kg day data taken from a p-type point contact germanium detector of the CDEX-10 experiment at China's Jinping underground laboratory. New low-mass dark matter searching channels, neutral current fermionic DM absorption (χ+A→ν+A) and DM-nucleus 3→2 scattering (χ+χ+A→ϕ+A), have been analyzed with an energy threshold of 160 eVee. No significant signal was found; thus new limits on the DM-nucleon interaction cross section are set for both models at the sub-GeV DM mass region. A cross section limit for the fermionic DM absorption is set to be 2.5×10^{-46}  cm^{2} (90% C.L.) at DM mass of 10  MeV/c^{2}. For the DM-nucleus 3→2 scattering scenario, limits are extended to DM mass of 5 and 14  MeV/c^{2} for the massless dark photon and bound DM final state, respectively.

[Functional outcomes of 100 patients with adenocarcinoma of the esophagogastric junction undergoing Cheng's GIRAFFE(®) reconstruction after proximal gastrectomy]

Objective: To investigate the functional outcomes and postoperative complications of Cheng's GIRAFFE reconstruction after proximal gastrectomy. Methods: A descriptive case series study was conducted. Clinical data of 100 patients with adenocarcinoma of the esophagogastric junction who underwent Cheng's GIRAFFE reconstruction after proximal gastrectomy in Cancer Hospital of University of Chinese Academy of Sciences (64 cases), Zhejiang Provincial Hospital of Chinese Medicine (24 cases), Lishui Central Hospital (10 cases), Huzhou Central Hospital (1 case) and Ningbo Lihuili Hospital (1 case) from September 2017 to June 2021 were retrospectively analyzed. Of 100 patients, 64 were males and 36 were females; the mean age was (61.3 ± 11.1) years and the BMI was (22.7±11.1) kg/m(2). For TNM stage, 68 patients were stage IA, 24 were stage IIA and 8 were stage IIB. Postoperative functional results and postoperative complications of radical gastrectomy with Giraffe reconstruction were analyzed and summarized. Gastroesophageal reflux disease questionnaire (RDQ) score and postoperative endoscopy were used to evaluate the occurrence of reflux esophagitis and its grade (grade N, grade A, grade B, grade C, and grade D from mild to severe reflux). The continuous data conforming to normal distribution were expressed as (mean ± standard deviation), and those with skewed distribution were presented as median (Q1, Q3). Results: All the 100 patients successfully completed R0 resection, including 77 patients undergoing laparoscopic surgery and 23 patients undergoing laparotomy. The Giraffe anastomosis time was (38.6±14.0) min; the blood loss was (73.0±18.4) ml; the postoperative hospital stay was 9.5 (8.2, 13.0) d; the hospitalization cost was (6.0±0.3) ten thousand yuan. Fourteen cases developed perioperative complications (14.0%), including 7 cases of pleural effusion or pneumonia, 3 cases of anastomotic leakage, 2 cases of gastric emptying disorder, 1 case of gastrointestinal hemorrhage and 1 case of anastomotic stenosis, who were all improved and discharged after symptomatic management. Patients were followed up for (33.3±1.6) months. Eight patients were found to have reflux symptoms by RDQ scale six months after surgery, and 11 patients (11/100,11.0%) were found to have reflux esophagitis by gastroscopy, including 6 in grade A, 3 in grade B, and 2 in grade C. All the patients could control their reflux symptoms with behavioral guidance or oral PPIs. Conclusion: Cheng's GIRAFFE reconstruction has good anti-reflux efficacy and gastric emptying function; it can be one of the choices of reconstruction methods after proximal gastrectomy.

[Investigate the thyroid function of radiation workers and analysis of influence factors]

Objective: To analyze the thyroid condition and influencing factors of radiation workers, and to provide scientific basis for radiation protection management. Methods: In April 2020, 4308 radiation workers from October 1, 2017 to September 30, 2019 were collected for occupational health examination in Hangzhou Occupational Disease Prevention and Treatment Hospital, the data included basic information, Thyroid hormone level and thyroid color doppler ultrasound results. The thyroid status of radiation workers in different subgroups was compared. The influencing factors of Thyroid nodule were analyzed by multiple logistic regression. Results: 616 radiation workers had abnormal thyroid gland (14.3%, 616/4308) . The main manifestations of thyroid gland abnormality were abnormal Thyroid nodule (5.1%, 220/4308) and abnormal TSH level (7.1%, 308/4308) . Compared with the male radiation workers, the abnormal rate of Thyroid nodule, T3 and Tsh in female radiation workers was higher (P<0.05) , and the abnormal rate of Thyroid nodule, T3 and T4 increased with the increase of working age (P<0.05) . Radiation Workers in non-rated medical institutions and private medical institutions had the highest detection rate of Thyroid nodule (P<0.05) , and there was no significant difference in thyroid abnormalities among Workers (P<0.05) . By multiple logistic regression analysis, Sex (female) , age and institution type (private) were all independent risk factors for Thyroid nodule (95% CI: 1.548~2.763、1.002~1.030, P<0.05) . Conclusion: Ionizing radiation can cause thyroid damage in radiation workers, so we should pay more attention to the radiation protection management of female, high age, private and district medical organizations, so as to protect the health of radiation workers.

Concussion susceptibility is mediated by spreading depolarization-induced neurovascular dysfunction

The mechanisms underlying the complications of mild traumatic brain injury, including post-concussion syndrome, post-impact catastrophic death, and delayed neurodegeneration remain poorly understood. This limited pathophysiological understanding has hindered the development of diagnostic and prognostic biomarkers and has prevented the advancement of treatments for the sequelae of mild traumatic brain injury.

We aimed to characterize the early electrophysiological and neurovascular alterations following repetitive mild traumatic brain injury and sought to identify new targets for the diagnosis and treatment of individuals at risk of severe post-impact complications. We combined behavioural, electrophysiological, molecular, and neuroimaging techniques in a rodent model of repetitive mild traumatic brain injury. In humans, we used dynamic contrast-enhanced MRI to quantify blood–brain barrier dysfunction after exposure to sport-related concussive mild traumatic brain injury.

Rats could clearly be classified based on their susceptibility to neurological complications, including life-threatening outcomes, following repetitive injury. Susceptible animals showed greater neurological complications and had higher levels of blood–brain barrier dysfunction, transforming growth factor β (TGFβ) signalling, and neuroinflammation compared to resilient animals. Cortical spreading depolarizations were the most common electrophysiological events immediately following mild traumatic brain injury and were associated with longer recovery from impact. Triggering cortical spreading depolarizations in mild traumatic brain injured rats (but not in controls) induced blood–brain barrier dysfunction. Treatment with a selective TGFβ receptor inhibitor prevented blood–brain barrier opening and reduced injury complications. Consistent with the rodent model, blood–brain barrier dysfunction was found in a subset of human athletes following concussive mild traumatic brain injury.

We provide evidence that cortical spreading depolarization, blood–brain barrier dysfunction, and pro-inflammatory TGFβ signalling are associated with severe, potentially life-threatening outcomes following repetitive mild traumatic brain injury. Diagnostic-coupled targeting of TGFβ signalling may be a novel strategy in treating mild traumatic brain injury.

Prevalence of bicuspid aortic valve in patients with aneurysmal sub-arachnoid hemorrhage: neurologic features and outcomes

Background

Intracranial aneurysm (IA) has been associated with bicuspid aortic valve (BAV) with prevalence of 6–10% which has led some to recommend routine surveillance for IA in BAV patients. Higher incidence of IA in BAV could signal towards systemic arteriopathy beyond the thoracic aorta. With CoA as an independent risk factor for IA formation, it is currently uncertain if the association between IA and BAV reflects the association of BAV and CoA, or the result of BAV-related systemic arterial changes.

Purpose

Despite this association, 2 small studies suggest no increased risk of the most important patient outcome: aneurysmal sub-arachnoid hemorrhage (aSAH). Our primary aim was identifying the prevalence of BAV in aSAH patients and compare it with that of a control group without aSAH. Secondary aims included neurologic outcomes of aSAH and anatomical characteristics of IA in BAV, and final disposition and outcome.

Methods

Patients (&gt;18 years age) with an accurate diagnosis of aSAH and at least one echocardiogram in the system between January 2000-December 2019 were identified from a prospectively maintained registry of aSAH admissions. Controls, without a diagnosis of SAH ever, were age- and gender-matched (1:2 cases:controls). BAV prevalence was echocardiographically-confirmed in all patients. Severity of aSAH was categorized using the modified Fisher (mFisher) and the World Federation of Neurological Scale (WFNS).

Results

A total of 488 aSAH cases and 990 controls were included in the final analysis with confirmed aortic valve status. The prevalence of BAV in aSAH patients was 1.2% (6/488) vs 3.5% (35/990) in controls, p=0.01. None of the aSAH cases were noted to have CoA, whereas 3 (0.3%; p=0.12) control patients had presence of both BAV and CoA. Within aSAH patients, BAV+aSAH were noted to be younger than tricuspid aortic valve (TAV)+aSAH (56±11 vs 68±14; p=0.03). Aneurysm size was smaller in the BAV+aSAH group (5±2 vs 7±4 in TAV+aSAH; p=0.31). The severity of the bleed was lesser in BAV+aSAH than TAV+aSAH (mFisher grade &gt;2 50% vs 74%; p=0.19, WFNS grade &gt;3 17% vs 36%; p=0.43) which is clinically significant. The BAV+aSAH group had higher disposition rate to home (67% vs 39%; p=0.21) with no difference in in-hospital mortality rates (17% vs 18%; p=0.93). BAV had lower odds on univariate and multivariate analyses adjusted for age/sex/body mass index (OR 0.33 [CI 0.14–0.81]; p=0.01, OR 0.23 [CI 0.08–0.65]; p=0.01) of presenting with aSAH.

Conclusion

Within a large prospective registry with accurate aSAH diagnoses, we found 3-times lower prevalence of echocardiographically-confirmed BAV as compared to non-aSAH controls. We observed 3-times higher prevalence of BAV in controls than among aSAH cases. In addition, size of intracranial aneurysms was clinically smaller in BAV patients, and the severity of SAH was significantly lesser in BAV from a clinical standpoint. Our findings argue against routine surveillance for IA in BAV patients without CoA.

Funding Acknowledgement

Type of funding sources: None.

Direct Detection Constraints on Dark Photons with the CDEX-10 Experiment at the China Jinping Underground Laboratory

We report constraints on the dark photon effective kinetic mixing parameter (κ) with data taken from two p-type point-contact germanium detectors of the CDEX-10 experiment at the China Jinping Underground Laboratory. The 90% confidence level upper limits on κ of solar dark photon from 205.4 kg-day exposure are derived, probing new parameter space with masses (m_{V}) from 10 to 300  eV/c^{2} in direct detection experiments. Considering dark photon as the cosmological dark matter, limits at 90% confidence level with m_{V} from 0.1 to 4.0  keV/c^{2} are set from 449.6 kg-day data, with a minimum of κ=1.3×10^{-15} at m_{V}=200  eV/c^{2}.

[Preliminary efficacy analysis of Cheng's Giraffe reconstruction after proximal gastrectomy in adenocarcinoma of esophagogastric junction]

Objective: To investigate the safety and feasibility of proximal partial gastrectomy with Cheng's Giraffe esophagogastric reconstruction for the treatment of early Siewert II adenocarcinoma of esophagogastric junction (AEG). Methods: Indication of Cheng's Giraffe esophagogastric reconstruction: (1) Siewert II AEG or Siewert III AEG with diameter < 4 cm; (2) preoperative staging as cT1-2N0M0. A descriptive case series study was carried out. Clinical data of 34 patients with Siewert II AEG undergoing proximal partial gastrectomy and Cheng's Giraffe esophagogastric reconstruction at Department of Abdominal Surgery of Zhejiang Cancer Hospital and Department of Gastrointestinal Surgery, The First Affiliated Hospital of Zhejiang University of Traditional Chinese Medicine from February to July 2018 were retrospectively collected and analyzed, including 14 cases in IA stage, 11 cases in IIA stage and 8 cases in IIB stage. Brief procedure of Cheng's Giraffe esophagogastric reconstruction was as follows: Firstly, 12 cm long tubular stomach was formed by longitudinal incision 4 cm away from the great curvature of the stomach. Secondly, the gastric fundus and His angle were formed. Finally, the distance from His angle to esophagal-tubular gastric anastomosis should be more than 5 cm. The reflux disease questionare (RDQ) scores, radionuclide gastric emptying scintigraphy, and 24-hour multichannel intraluminal (MII)-pH monitoring technology were used to evaluate postoperative gastric emptying and gastroesophageal reflux. Result: All 34 patients successfully completed proximal partial gastrectomy with Cheng's Giraffe esophagogastric reconstruction, including 13 cases by open surgery and 21 cases by laparoscopic surgery. The operation time was (144.6±39.8) minutes, the blood loss during operation was (35.4±17.2) ml. No laparoscopic case was converted to open surgery and no postoperative complication was observed. The postoperative hospital stay was (8.4±2.5) days. The postoperative RDQ score was 4.4±3.1 one month after operation, and 3.3±2.5 six months after operation. Gastric-half emptying time was (67.0±21.5) minutes, and the residual ratio was (52.2±7.7)% in 1 hour, (36.4±3.1)% in 2 hours and (28.8±3.6)% in 3 hours at postoperative 1-month. The 24-hour MII-pH monitoring at postoperative 2-month revealed the frequency of acid reflux was (12.6±7.9) times, frequency of non-acid reflux was (19.6±9.7) times, DeMeester score was 5.8±2.9. Conclusion: Cheng's Giraffe esophagogastric reconstruction is safe and feasible in the treatment of Siewert type II AEG, and has good dynamic and anti-reflux effects.

Search for Light Weakly-Interacting-Massive-Particle Dark Matter by Annual Modulation Analysis with a Point-Contact Germanium Detector at the China Jinping Underground Laboratory

We present results on light weakly interacting massive particle (WIMP) searches with annual modulation (AM) analysis on data from a 1-kg mass p-type point-contact germanium detector of the CDEX-1B experiment at the China Jinping Underground Laboratory. Datasets with a total live time of 3.2 yr within a 4.2-yr span are analyzed with analysis threshold of 250 eVee. Limits on WIMP-nucleus (χ-N) spin-independent cross sections as function of WIMP mass (m_{χ}) at 90% confidence level (C.L.) are derived using the dark matter halo model. Within the context of the standard halo model, the 90% C.L. allowed regions implied by the DAMA/LIBRA and CoGeNT AM-based analysis are excluded at >99.99% and 98% C.L., respectively. These results correspond to the best sensitivity at m_{χ}<6  GeV/c^{2} among WIMP AM measurements to date.

Constraints on Spin-Independent Nucleus Scattering with sub-GeV Weakly Interacting Massive Particle Dark Matter from the CDEX-1B Experiment at the China Jinping Underground Laboratory

We report results on the searches of weakly interacting massive particles (WIMPs) with sub-GeV masses (m_{χ}) via WIMP-nucleus spin-independent scattering with Migdal effect incorporated. Analysis on time-integrated (TI) and annual modulation (AM) effects on CDEX-1B data are performed, with 737.1 kg day exposure and 160 eVee threshold for TI analysis, and 1107.5 kg day exposure and 250 eVee threshold for AM analysis. The sensitive windows in m_{χ} are expanded by an order of magnitude to lower DM masses with Migdal effect incorporated. New limits on σ_{χN}^{SI} at 90% confidence level are derived as 2×10^{-32}∼7×10^{-35}  cm^{2} for TI analysis at m_{χ}∼50-180  MeV/c^{2}, and 3×10^{-32}∼9×10^{-38}  cm^{2} for AM analysis at m_{χ}∼75  MeV/c^{2}-3.0  GeV/c^{2}.

[Analysis of radiation workers health status in a city]

Objective: To investigate the health status of radiation workers in a city and provide evidence for the health management of radiation workers. Methods: To investigate the health status of radiation workers in a city and provide evidence for the health management of radiation workers. Results: The majority of radiation workers are engaged in diagnostic radiology, male is more than female. The abnormal rate of micronuclear (0.59‰) and chromosome aberration (0.47%) was highest in nuclear medicine workers. The abnormal rate of micronuclear and chromosome aberration was similar with interventional and diagnostic radiology. Expect for micronuclear (χ(2)=32.945, P<0.01) and chromosome aberration (χ(2)=75149.737, P<0.01) , other radiation sensitive indicators have no difference. The abnormal rate of thyroid function (18.8%) (χ(2)=12.084, P<0.01) , micronuclear (0.25‰) (χ(2)=57.359, P<0.01) , chromosome aberration (0.08%) (χ(2)=17.209, P<0.01) in group whose service length exceeding 20 years was higher than other service length groups. There is no statistical difference in other radiation sensitive indicators among different service length group. Conclusion: Long-term low doses of ionizing radiation could affect radiation worker's health, expecially radiation workers engaged in nuclear medicine and radiotherapy. We must pay attention to occupaitonal health care and management to ensure radiation worker's health.

Limits on Light Weakly Interacting Massive Particles from the First 102.8 kg×day Data of the CDEX-10 Experiment

We report the first results of a light weakly interacting massive particles (WIMPs) search from the CDEX-10 experiment with a 10 kg germanium detector array immersed in liquid nitrogen at the China Jinping Underground Laboratory with a physics data size of 102.8 kg day. At an analysis threshold of 160 eVee, improved limits of 8×10^{-42} and 3×10^{-36}  cm^{2} at a 90% confidence level on spin-independent and spin-dependent WIMP-nucleon cross sections, respectively, at a WIMP mass (m_{χ}) of 5  GeV/c^{2} are achieved. The lower reach of m_{χ} is extended to 2  GeV/c^{2}.

Study of inactive layer uniformity and charge collection efficiency of a p-type point-contact germanium detector

The characteristics of the surface inactive layer of a 1-kg-mass p-type point-contact germanium detector were studied. The thickness of the inactive layer and its uniformity on the top and lateral surfaces were measured. A charge collection efficiency function was developed according to the Monte Carlo simulation to describe the charge collection capacity along the depth within this inactive layer. In the energy range below 18keV, the surface, bulk, and total spectra of ⁵⁷Co, ¹³³Ba, ¹³⁷Cs, and ⁶⁰Co from simulations based on the charge collection efficiency function were well consistent with those from experiments.

Preparation and lithium storage performances of mesoporous Fe₃O₄@C microcapsules

Fe(3)O(4)@C microcapsules were prepared using carbon-coated α-FeOOH nanorods as precursors, which were synthesized via two-step hydrothermal reactions. During the subsequent sintering procedure, α-FeOOH was reduced to Fe(3)O(4) by carbon, accompanied by the formation of mesopores. In Fe(3)O(4)@C microcapsules, mesoporous Fe(3)O(4) nanorods are coated with amorphorous carbon layers. The Fe(3)O(4)/C composites with such special structures demonstrate high specific capacity and good cyclic stability as anode materials in Li test cells.

Expression of protein tyrosine phosphatase alpha (RPTPalpha) in human breast cancer correlates with low tumor grade, and inhibits tumor cell growth in vitro and in vivo

Tyrosine phosphorylation is controlled by a balance of tyrosine kinases (PTKs) and protein tyrosine phosphatases (PTPs). Whereas the contribution of PTKs to breast tumorigenesis is the subject of intense scrutiny, the potential role of PTPs is poorly known. RPTPalpha is implicated in the activation of Src family kinases, and regulation of integrin signaling, cell adhesion, and growth factor responsiveness. To explore its potential contribution to human neoplasia, we surveyed RPTPalpha protein levels in primary human breast cancer. We found RPTPalpha levels to vary widely among tumors, with 29% of cases manifesting significant overexpression. High RPTPalpha protein levels correlated significantly with low tumor grade and positive estrogen receptor status. Expression of RPTPalpha in breast carcinoma cells led to growth inhibition, associated with increased accumulation in G0 and G1, and delayed tumor growth and metastasis. To our knowledge, this is the first example of a study correlating expression level of a specific bona fide PTP with neoplastic disease status in humans.

Association between receptor protein-tyrosine phosphatase RPTPalpha and the Grb2 adaptor. Dual Src homology (SH) 2/SH3 domain requirement and functional consequences

Receptor protein-tyrosine phosphatase RPTPalpha is found associated in vivo with the adaptor protein Grb2. Formation of this complex, which contains no detectable levels of Sos, is known to depend on a C-terminal phosphorylated tyrosine residue (Tyr798) in RPTPalpha and on the Src homology (SH) 2 domain in Grb2 (, ). We show here that association of Grb2 with RPTPalpha also involves a critical function for the C-terminal SH3 domain of Grb2. Furthermore, Grb2 SH3 binding peptides interfere with RPTPalpha-Grb2 association in vitro, and the RPTPalpha protein can dissociate the Grb2-Sos complex in vivo. These observations constitute a novel mode of Grb2 association and suggest a model in which association with a tyrosine-phosphorylated protein restricts the repertoire of SH3 binding proteins with which Grb2 can simultaneously interact. The function of the Tyr798 tyrosine phosphorylation/Grb2 binding site in RPTPalpha was studied further by expression of wild type or mutant RPTPalpha proteins in PC12 cells. In these cells, wild type RPTPalpha interferes with acidic fibroblast growth factor-induced neurite outgrowth; this effect requires both the catalytic activity and the Grb2 binding Tyr798 residue in RPTPalpha. In contrast, expression of catalytically active RPTPalpha containing a mutated tyrosine phosphorylation/Grb2 association site enhances neurite outgrowth. Our observations associate a functional effect with tyrosine phosphorylation of, and ensuing association of signaling proteins with, a receptor protein-tyrosine phosphatase and raise the possibility that RPTPalpha association may modulate Grb2 function and vice versa.

Expression of polyphosphate kinase inhibits the glucose uptake in Escherichia coli

This paper examines the effects of phosphate pool and expression of polyphosphate kinase on glucose uptake by expressing the polyphosphate kinase under the control of lac promoter. The E. coli transformant of pL1, containing an IPTG controllable element for polyphosphate kinase expression, showed that the total intracellular phosphate significantly increased. However, the rate of glucose uptake by the resting plasmid-bearing cells with IPTG induction significantly decreased. These findings suggest that the polyphosphate can not directly function as an energy source in E. coli or at least not as a good energy supplier.

Topological precision in the thalamic projection to neonatal mouse barrel cortex

Somatosensory thalamus and cortex in rodents contain topological representations of the facial whisker pad. The thalamic representation of a single whisker ("barreloid") is presumed to project exclusively to the cortical representation ("barrel") of the same whisker; however, it was not known when this correspondence is established during early development, nor how precise the thalamocortical projection is at birth, before formation of barrels and barreloids. To answer these questions, we retrogradely labeled thalamocortical projection neurons in fixed brain slices from 0-8 d old (P0-P8) mice, by placing paired deposits of two fluorescent dyes in adjacent barrels or (before barrel formation) in adjacent loci in upper cortical layers. At all ages studied, a negligible fraction of the retrogradely labeled cells was double labeled, implying that branches of single thalamocortical axons never extended within layer IV over an area wider than a single barrel. In P0 preparations, 70% of paired dye deposits placed 75-200 microns apart resulted in statistically significant segregation of labeled cell clusters in the thalamus. Quantitative analysis indicated that on P0 about 70% of thalamocortical axons were within 1.3 presumptive barrel diameters from their topologically precise target. In P4-P8 preparations, the great majority of thalamic cells retrogradely labeled from a single barrel were found in a single barreloid, implying a 1:1 projection of barreloids to barrels. The postnatal increase in topological precision was reproduced by a computer simulation, which assumed that many aberrant axons corrected their initial targeting error by extending terminal arborizations asymmetrically, towards the center of their appropriate barrel.

Clear cell carcinoma of salivary glands: immunohistochemical evaluation of clear tumor cells

A total of 14 cases of clear cell carcinoma of salivary glands were evaluated by immunohistochemical methods using monoclonal antibodies to cytokeratin (K1.1 and K8.12), vimentin, S-100 alpha and beta subunits, neuron-specific enolase (NSE), glial fibrillary acidic protein (GFAP), MAM-3 and MAM-6 antigens and proliferating cell nuclear antigen (PCNA), as well as polyclonal antibodies to lysozyme (Ly), lactoferrin (la) and Alpha-1-antichymotrypsin (alpha 1-Ach). Histopathologically, the carcinoma was characterized by round or polygonal tumor cells with cytoplasm that does not stain with hematoxylin and eosin, nuclei with little pleomorphism and few or no mitotic figures, and growing in solid sheets, small nests or cords with collagenous stroma. Cytokeratin KL1 and K8.12 was present in few tumor cells with almost negligible to strong reaction in all cases, vimentin in 6, GFAP in 5 cases with multiple-expression of cytokeratin K8.12, vimentin and GFAP in 5 cases. S-100 protein immunoreactivity was the most prominent feature with more intense reaction of S-100 beta than S-100 alpha subunit. NSE reactivity was seen in 6 cases. Ly, La, a1-ch, MAM-3 and MAM-6 antigens were localized in clear cells with various reaction intensities. The authors conclude that the clear tumor cells in clear cell carcinoma of salivary glands are not myoepithelial in origin but epithelial or neuroectodermal/neural crest in origin, showing ductal differentiation at the immunohistochemical level.

Organized growth of thalamocortical axons from the deep tier of terminations into layer IV of developing mouse barrel cortex

The thalamocortical projection to rodent somatosensory ("barrell") cortex is highly ordered in both the radial and the tangential dimensions. During a brief period of postnatal development, thalamocortical axons establish two tiers of terminations, in the deep layers and in layer IV, and form whisker-specific clusters within layer IV; however, little is known about the cues that guide them to their appropriate radial and tangential positions. To gain insight into potential mechanisms underlying this process, we studied the development of thalamocortical termination patterns in mouse barrel cortex at high spatial resolution. Developing thalamocortical axons were labeled in fixed slices with the lipophilic carbocyanine dye Dil and imaged with a laser scanning confocal microscope. On the day of birth (postnatal day 0, P0) axons coursed through layers VI and V, with little or no branching. By P2 the lower tier of terminations, at the border of layers VI and V, was clearly identifiable. Below this tier axons coursed obliquely or tangentially, forming a dense meshwork of intersecting fibers, but with no apparent branching. By P4 the upper tier of terminations, in layer IV, was clearly recognizable, and consisted of periodic, dense clusters of terminal arborizations. In marked contrast to the oblique and apparently disorderly course followed by axons in layer VI and lower layer V, axons in upper layer V heading toward the upper tier were organized in loose bundles running radially, suggesting that axons destined to terminate in a particular layer IV barrel had already reached their appropriate tangential coordinates within the lower tier. Thus, the pattern of thalamocortical terminations in layer IV seems to be projected from the deep tier of terminations, and does not develop from an initially profuse arborization pattern through pruning of inappropriate branches.