Dual-branch feature fusion S3D V-Net network for lung nodules segmentation.

BACKGROUND: Accurate segmentation of lung nodules can help doctors get more accurate results and protocols in early lung cancer diagnosis and treatment planning, so that patients can be better detected and treated at an early stage, and the mortality rate of lung cancer can be reduced. PURPOSE: Currently, the improvement of lung nodule segmentation accuracy has been limited by his heterogeneous performance in the lungs, the imbalance between segmentation targets and background pixels, and other factors. We propose a new 2.5D lung nodule segmentation network model for lung nodule segmentation. This network model can well improve the extraction of edge information of lung nodules, and fuses intra-slice and inter-slice features, which makes good use of the three-dimensional structural information of lung nodules and can more effectively improve the accuracy of lung nodule segmentation. METHODS: Our approach is based on a typical encoding-decoding network structure for improvement. The improved model captures the features of multiple nodules in both 3-D and 2-D CT images, complements the information of the segmentation target's features and enhances the texture features at the edges of the pulmonary nodules through the dual-branch feature fusion module (DFFM) and the reverse attention context module (RACM), and employs central pooling instead of the maximal pooling operation, which is used to preserve the features around the target and to eliminate the edge-irrelevant features, to further improve the performance of the segmentation of the pulmonary nodules. RESULTS: We evaluated this method on a wide range of 1186 nodules from the LUNA16 dataset, and averaging the results of ten cross-validated, the proposed method achieved the mean dice similarity coefficient (mDSC) of 84.57%, the mean overlapping error (mOE) of 18.73% and average processing of a case is about 2.07 s. Moreover, our results were compared with inter-radiologist agreement on the LUNA16 dataset, and the average difference was 0.74%. CONCLUSION: The experimental results show that our method improves the accuracy of pulmonary nodules segmentation and also takes less time than more 3-D segmentation methods in terms of time.

Production of Indigo by Recombinant Escherichia coli with Expression of Monooxygenase, Tryptophanase, and Molecular Chaperone.

Indigo is an important pigment widely used in industries of food, cosmetics, and textile. In this work, the styrene monooxygenase StyAB from Pseudomonas putida was co-expressed with the tryptophanase TnaA and the chaperone groES-groEL in Escherichia coli for indigo production. Over-expression of the gene styAB endowed the recombinant E. coli AB with the capacity of indigo biosynthesis from indole and tryptophan. Tryptophan fermentation in E. coli AB generated about five times more indigo than that from indole, and the maximum 530 mg/L of indigo was obtained from 1.2 mg/mL of tryptophan. The gene TnaA was then co-expressed with styAB, and the tryptophanase activity significantly increased in the recombinant E. coli ABT. However, TnaA expression led to a decrease in the activity of StyAB and indigo yield in E. coli ABT. Furthermore, the plasmid pGro7 harboring groES-groEL was introduced into E. coli AB, which obviously promoted the activity of StyAB and accelerated indigo biosynthesis in the recombinant E. coli ABP. In addition, the maximum yield of indigo was further increased to 550 mg/L from 1.2 mg/mL of tryptophan in E. coli ABP. The genetic manipulation strategy proposed in this work could provide new insights into construction of indigo biosynthesis cell factory for industrial production.

Case Report: Toripalimab Combined With Anlotinib in a Patient With Metastatic Upper Tract Urothelial Carcinoma After Pembrolizumab Failure.

Urothelial carcinoma is the most common primary upper tract urinary carcinoma. If surgery, chemotherapy, and immunotherapy fail, the prognosis for upper tract urinary carcinoma is extremely poor. Immunotherapy combined with antiangiogenesis therapy is a new therapeutic regimen with a synergistic antitumor effect. We present a case of metastatic upper tract urinary carcinoma in which the patient underwent surgery and treatment with gemcitabine combined with platinum-based chemotherapy. Radiotherapy and second-line immunotherapy (pembrolizumab) were administered after the cancer had progressed to the left lymph node of the abdominal aorta in the umbilical plane. However, the patient developed liver metastases while being treated with pembrolizumab. He was administered off-label immunotherapy (toripalimab) combined with antiangiogenesis therapy (anlotinib) and achieved a long-term clinical response for over 25 months. Toripalimab combined with anlotinib has potential therapeutic value for locally advanced or metastatic upper tract urinary carcinoma in patients who had previously received platinum-based chemotherapy and had disease progression or after treatment with a PD-1 inhibitor.

Higher pharyngeal epithelial gene expression of angiotensin-converting Enzyme-2 in patients with upper respiratory infection.

We analyzed the expression of ACE2 in the pharyngeal epithelium and examined its relationship with clinical features and serological parameters in patients with upper respiratory infection (URI). The expression level of the ACE2 gene was significantly higher in patients with URI (n = 125) than in healthy control (HC) individuals (n = 52) (p < 0.0001). The ACE2 gene expression level was significantly and positively correlated with age (r=0.1799, p = 0.0447) and body temperature (r=0.1927, p = 0.0427), which may help explain increasing coinfections with SARS-CoV-2 and other respiratory pathogens.

Near-infrared photoresponse of femtosecond-laser processed Se-doped silicon n+ - n photodiodes.

Se-doped silicon was prepared using deposited Si-Se bilayer thin films followed by femtosecond-laser irradiation. n+-n photodiodes were fabricated from this material for the first time, to the best of our knowledge. The effects of the annealing temperature and the reverse bias voltage on the near-infrared responsivity were investigated. The photodiode exhibits optimal rectification and photoresponse at an annealing temperature of 500°C. At a 12 V bias, a responsivity of 2.41 A/W at 1064 nm is obtained. The linear increase at bias from 0 to 10 V and faster-than-linear increase at bias from 10 to 12 V for the responsivity are observed with the increase of the bias voltage. The results suggest that the gain mechanism is most likely to be a photoconductive gain.

Photosensitivity of Te-doped silicon photodiodes fabricated using femtosecond laser irradiation.

Microstructured Te-doped silicon is prepared via a femtosecond laser irradiating Si coated with Si-Te bilayer films, and photodiodes are successfully fabricated from this material. The samples are thermally annealed at 773 K for three different time durations. The effects of annealing time on microstructures, infrared absorptance, and photosensitivity of Te-doped silicon are investigated. From the scanning electronic microscope images and the optical absorptance spectra, the results show that the infrared absorptance decreases with the increase of annealing time durations, while the infrared photoresponse follows an opposite tendency. At 1064 nm, the responsivity achieves 2.4836 A/W at -10 V reverse bias for the Te-doped silicon photodiode annealed at 775 K for 2 h, which is higher than that of usual commercial Si photodiodes. These results are important for the fabrication of Te-doped silicon and facilitate its application in infrared detectors.

Targeted cellular uptake and siRNA silencing by quantum-dot nanoparticles coated with ß-cyclodextrin coupled to amino acids.

Quantum dots (QDs) have the potential to serve as photostable beacons to track siRNA delivery, which is fast becoming an attractive approach to probe gene function in cells. In this paper, we synthesized QD nanoparticles coated with ß-cyclodextrin (ß-CD) coupled to amino acids with different surface charges (positive, negative, and neutral) through direct ligand-exchange reactions and used them to deliver siRNA. We found that these QDs are diffluent in biological buffer with high colloidal stability and have strong optical emission properties similar to those of tri-n-octylphosphine oxide (TOPO)-coated QDs and also have a long fluorescence lifetime (12.5 ns for L-His-ß-CD-coated CdSe/ZnSe QDs). The results of in vitro cytotoxicity and internalization of these modified QDs in normal and cancer cells showed that the ß-CD coupled to amino acid outlayers greatly improved the biocompatibility of QDs, and conferred with lower cytotoxicity even at very high concentration. In particular, the L-His-ß-CD-coated CdSe/ZnSe QDs presented lower cytotoxicity to these cells (CC(50) value is 180.6±3.4 µg mL(-1) in ECV-304 cells for 48 h). Transmission electron microscope (TEM) images showed that the QDs were localized in vesicles in the cytoplasm of the cells. Furthermore, compared with existing transfection agents, gene-silencing efficiency of the modified QDs was slightly improved for HPV18 E6 gene in HeLa cells by gel electrophoresis analysis. Finally, the unique optical properties of QDs allow visible imaging of siRNA delivery in live cells. Taken together, our study not only provides new insights into the mechanisms of amino acid mediated delivery, but also greatly facilities the monitoring of gene-silencing studies.

Gadolinium-induced oxidative stress triggers endoplasmic reticulum stress in rat cortical neurons.

Introduction of Gadolinium (Gd) to the nervous system is linked to the development of neurotoxicity involving both oxidative and endoplasmic reticulum (ER) stress. Gd levels (0.2-20 µm) in the form of gadolinium trichloride (GdCl(3)) cause neurotoxicity in vitro. We investigated the signaling pathways in primary cultured rat cortical neurons and tested whether GdCl(3) induced oxidative and ER stress. Results showed that Gd-induced neural cell death followed a rapid accumulation of intracellular reactive oxygen species. In addition, Gd exposure resulted in spliced X-box binding protein 1 mRNA and increased expression of binding immunoglobulin protein, thus activating transcription factor 4 (ATF4), ATF6, and C/EBP homologous protein mRNA. Up-regulated expression of binding immunoglobulin protein is a hallmark of ER stress and C/EBP homologous protein is an ER stress-related pro-apoptotic transcription factor. Activation of ER stress downstream substrates, inositol-requiring kinase 1 and ATF6, was also observed in Gd-treated cells. The neurotoxic effects of Gd were blocked by the antioxidant N-acetylcysteine. Results demonstrated that Gd-induced cytotoxicity in neurons occurs via oxidative injury and ER stress-related signal transduction, thus offering new insight into the neurotoxicology of gadolinium.