572 research outputs found
Chinese Government Procurement Legislation: Process, Patterns and Future Reform
The authors agreed with the integration of Law on Tenders and Bids and unified government procurement legislation. The idea of Improvement tries to maintain the existing project procurement system in bidding. As with previously mentioned, Law on Tenders and Bids makes the practice of private procurement activities within the adjustment range is flawed jurisprudence and should be adjusted rather than maintained. Even if the bidding is a general way to choose suppliers, purely private procurement should also be allowed to trade on the basis of bilateral consultations and selected procedures as they see fit rather than force them to apply rigid “Bidding” provisions
Boron neutron capture therapy induces cell cycle arrest and cell apoptosis of glioma stem/progenitor cells in vitro
BACKGROUND: Glioma stem cells in the quiescent state are resistant to clinical radiation therapy. An almost inevitable glioma recurrence is due to the persistence of these cells. The high linear energy transfer associated with boron neutron capture therapy (BNCT) could kill quiescent and proliferative cells. METHODS: The present study aimed to evaluate the effects of BNCT on glioma stem/progenitor cells in vitro. The damage induced by BNCT was assessed using cell cycle progression, apoptotic cell ratio and apoptosis-associated proteins expression. RESULTS: The surviving fraction and cell viability of glioma stem/progenitor cells were decreased compared with differentiated glioma cells using the same boronophenylalanine pretreatment and the same dose of neutron flux. BNCT induced cell cycle arrest in the G2/M phase and cell apoptosis via the mitochondrial pathway, with changes in the expression of associated proteins. CONCLUSIONS: Glioma stem/progenitor cells, which are resistant to current clinical radiotherapy, could be effectively killed by BNCT in vitro via cell cycle arrest and apoptosis using a prolonged neutron irradiation, although radiosensitivity of glioma stem/progenitor cells was decreased compared with differentiated glioma cells when using the same dose of thermal neutron exposure and boronophenylalanine pretreatment. Thus, BNCT could offer an appreciable therapeutic advantage to prevent tumor recurrence, and may become a promising treatment in recurrent glioma
Advances in multi-modal non-invasive imaging techniques in the diagnosis and treatment of polypoidal choroidal vasculopathy
Polypoidal choroidal vasculopathy (PCV) is a disease characterized by subretinal pigment epithelium (RPE) orange-red polypoidal lesions and abnormal branching neovascular networks (BNNs). In recent years, various non-invasive imaging technologies have rapidly developed, especially the emergence of optical coherence tomography angiography (OCTA), multi-spectral imaging, and other technologies, which enable the observation of more features of PCV. In addition, these technologies are faster and less invasive compared to indocyanine green angiography (ICGA). Multi-modal imaging, which combined multiple imaging techniques, provides important references for the diagnosis and treatment of PCV with the assistance of regression models, deep learning, and other algorithms. In this study, we reviewed the non-invasive imaging techniques, multi-modal imaging diagnosis, and multi-scene therapeutic applications of PCV, with the aim of providing a reference for non-invasive multi-modal diagnosis and treatment of PCV
A Unified Pyramid Recurrent Network for Video Frame Interpolation
Flow-guide synthesis provides a common framework for frame interpolation,
where optical flow is typically estimated by a pyramid network, and then
leveraged to guide a synthesis network to generate intermediate frames between
input frames. In this paper, we present UPR-Net, a novel Unified Pyramid
Recurrent Network for frame interpolation. Cast in a flexible pyramid
framework, UPR-Net exploits lightweight recurrent modules for both
bi-directional flow estimation and intermediate frame synthesis. At each
pyramid level, it leverages estimated bi-directional flow to generate
forward-warped representations for frame synthesis; across pyramid levels, it
enables iterative refinement for both optical flow and intermediate frame. In
particular, we show that our iterative synthesis can significantly improve the
robustness of frame interpolation on large motion cases. Despite being
extremely lightweight (1.7M parameters), UPR-Net achieves excellent performance
on a large range of benchmarks. Code will be available soon.Comment: arXiv admin note: text overlap with arXiv:2206.08572 by other author
New findings on retinal microvascular changes in patients with primary COVID-19 infection: a longitudinal study
PurposeTo investigate the longitudinal alterations of retinal microvasculature in patients with primary coronavirus disease 2019 (COVID-19) infection.MethodsA cohort of participants, who had never been infected with COVID-19, was recruited between December 2022 and May 2023 at Peking Union Medical College Hospital in Beijing, China. Participants underwent comprehensive ophthalmologic examinations and fundus imaging, which included color fundus photography, autofluorescence photography, swept-source optical coherence tomography (SS-OCT) and SS-OCT angiography (SS-OCTA). If participants were infected with COVID-19 during the study, follow-ups with consistent imaging modality were conducted within one week and two months after recovery from the infection.Results31 patients (61 eyes), with a mean age of 31.0 ± 7.2 years old, were eligible for this study. All participants contracted mild COVID-19 infection within one month of baseline data collection. The average period was 10.9 ± 2.0 days post-infection for the first follow-up and 61.0 ± 3.5 days for the second follow-up. No clinical retinal microvasculopathy features were observed during the follow-ups. However, SS-OCTA analysis showed a significant increase in macular vessel density (MVD) from 60.76 ± 2.88% at baseline to 61.59 ± 3.72%(p=0.015) at the first follow-up, which subsequently returned to the baseline level of 60.23 ± 3.33% (p=0.162) at the two-month follow-up. The foveal avascular zone (FAZ) remained stable during the follow-ups with areas of 0.339 ± 0.097mm2, 0.342 ± 0.093mm2, and 0.344 ± 0.098mm2 at the baseline, first follow-up (p=0.09) and second follow-up (p=0.052), respectively. Central macular thickness, cube volume and ganglion cell-inner plexiform layer showed a transient decrease at the first follow-up(p<0.001, p=0.039, p=0.002, respectively), and increased to baseline level at the two-month follow-up(p=0.401, p=0.368, p=0.438, respectively).ConclusionMild COVID-19 infection may temporarily and reversibly impact retinal microvasculature, characterized by a transient increase in retinal blood flow during the early recovery phase, which returns to the pre-infection level two months post-infection
Learning Two-Stream CNN for Multi-Modal Age-related Macular Degeneration Categorization
This paper tackles automated categorization of Age-related Macular
Degeneration (AMD), a common macular disease among people over 50. Previous
research efforts mainly focus on AMD categorization with a single-modal input,
let it be a color fundus image or an OCT image. By contrast, we consider AMD
categorization given a multi-modal input, a direction that is clinically
meaningful yet mostly unexplored. Contrary to the prior art that takes a
traditional approach of feature extraction plus classifier training that cannot
be jointly optimized, we opt for end-to-end multi-modal Convolutional Neural
Networks (MM-CNN). Our MM-CNN is instantiated by a two-stream CNN, with
spatially-invariant fusion to combine information from the fundus and OCT
streams. In order to visually interpret the contribution of the individual
modalities to the final prediction, we extend the class activation mapping
(CAM) technique to the multi-modal scenario. For effective training of MM-CNN,
we develop two data augmentation methods. One is GAN-based fundus / OCT image
synthesis, with our novel use of CAMs as conditional input of a high-resolution
image-to-image translation GAN. The other method is Loose Pairing, which pairs
a fundus image and an OCT image on the basis of their classes instead of eye
identities. Experiments on a clinical dataset consisting of 1,099 color fundus
images and 1,290 OCT images acquired from 1,099 distinct eyes verify the
effectiveness of the proposed solution for multi-modal AMD categorization
All-cause mortality in metabolically healthy individuals was not predicted by overweight and obesity
BACKGROUND
Metabolically healthy obesity (MHO) and metabolically healthy overweight (MH-OW) have been suggested to be important and emerging phenotypes with an increased risk of cardiovascular disease (CVD). However, whether MHO and MH-OW are associated with all-cause mortality remains inconsistent.
METHODS The association of MHO and MH-OW and all-cause mortality was determined in a Chinese community-based prospective cohort study (the Kailuan study), including 93,272 adults at baseline. Data were analyzed from 2006 to 2017. Participants were categorized into 6 mutually exclusive groups, according to BMI and metabolic syndrome (MetS) status. The primary outcome was all-cause death, and accidental deaths were excluded.
RESULTS During a median follow-up of 11.04 years (interquartile range, 10.74-11.22 years), 8977 deaths occurred. Compared with healthy participants with normal BMI (MH-NW), MH-OW participants had the lowest risk of all-cause mortality (multivariate-adjusted HR [aHR], 0.926; 95% CI, 0.861-0.997), whereas there was no increased or decreased risk for MHO (aHR, 1.009; 95% CI, 0.886-1.148). Stratified analyses and sensitivity analyses further validated that there was a nonsignificant association between MHO and all-cause mortality.
CONCLUSIONS Overweight and obesity do not predict increased risk of all-cause mortality in metabolic healthy Chinese individuals
Central retinal vein occlusion in patients with metastatic solid tumors on tyrosine kinase inhibitors: a report of case series and literature review
BackgroundCentral retinal vein occlusion (CRVO) is a rare adverse effect related to the use of tyrosine kinase inhibitors (TKIs) in patients with metastatic malignancies, which has only been reported in several case reports.Case presentationWe reported the case series of three CRVO patients on regular regimens of TKIs as part of targeted therapies for metastatic malignancies, all of whom were otherwise healthy with no or well-controlled systemic conditions. All these patients received injections of intravitreal dexamethasone implant (IDI) and achieved a fluid-free macula at the end of the visit. In addition, we reviewed the existing literature on this subject and present here an updated analysis of the related TKIs, ocular presentation, treatment, and prognosis.ConclusionAll patients diagnosed with CRVO on TKIs received dexamethasone implant treatment and obtained a fluid-free macula. We would like to raise awareness among our colleague oncologists about the possibility of CRVO related to TKI use and the necessity for patients to be screened regularly by a retinal specialist
The Zfx gene is expressed in human gliomas and is important in the proliferation and apoptosis of the human malignant glioma cell line U251
Background: Zfx is a zinc finger protein of the Zfy family, whose members are highly conserved in vertebrates. Zfx is a shared transcriptional regulator of both embryonic stem cells (ESC) and hematopoietic stem cells (HSC), which suggests a common genetic basis of self-renewal in embryonic and adult stem cells. The level of Zfx expression correlates with aggressiveness and severity in many cancer types, including prostate cancer, breast cancer, and leukemia. However, the importance of Zfx in human glioma is largely unknown. In the present study, we examined the role of Zfx in human glioma. Methods. We detected expression levels of Zfx mRNA in U251 cells, U87 cells, U373 cells, and A172 cells by semi-quantitative RT-PCR. To analyze the expression of Zfx mRNA in glioma tissues, we performed real-time quantitative PCR on 35 pathologically confirmed glioma samples (Grade I-4cases, Grade II-13cases, Grade III-11cases, and Grade IV-7cases) and on 5 noncancerous brain tissue samples. We used lentivirus-mediated small interfering RNAs (siRNAs) to knock down Zfx expression in the human malignant glioma cell line U251. Changes in Zfx target gene expression were determined by real-time RT-PCR. Cell proliferation was examined by a High Content Screening assay. DNA synthesis in proliferating cells was determined by BrdU incorporation. Cell cycle distribution and apoptosis were detected by flowcytometric analysis. Results: We discovered that Zfx mRNA was expressed in U251 cells, U87 cells, U373 cells, and A172 cells. The expression level of Zfx is significantly higher in gliomas compared to noncancerous brain tissue. Using a lentivirus-based RNAi approach, Zfx expression was significantly inhibited in human glioblastoma U251 cells. The effects of Zfx knockdown on cell proliferation, cell cycle distribution, and apoptosis were assessed. Inhibition of Zfx expression in U251 cells by RNAi significantly impaired cell proliferation, increased apoptosis, and arrested cells in S phase. Conclusions: The results of our study demonstrate that the Zfx gene is highly expressed in glioma tissue and in glioma cell lines. Furthermore, Zfx may play a critical role in cell proliferation, cell cycle distribution, and apoptosis of human malignant glioma cells. © 2011 Zhou et al; licensee BioMed Central Ltd
Non-technical factors on ophthalmology education: a narrative review
Ophthalmology education is increasingly influenced by non-technical factors. This paper examines the multifaceted influences on ophthalmology education, focusing on direct and indirect factors that have shaped the training and wellbeing of ophthalmology students and residents. A systematic search of PubMed and Embase was carried out, searching date was from inception to 01/07/2024. A total of 8,232 articles were screened, of which 7,976 were excluded following abstract review. After reading the remaining 256 articles in full, a further 228 were excluded. A total of 28 original articles were included in this systematic review. The non-technical factors that influenced ophthalmology education included various crisis, inadequate curricular time, training resources, lack of training standardization and shortage of financial support and teaching resources. The review summarizes the influences on ophthalmology education of various non-technical factors, thereby helping educators improve the training methods
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