Research on the application of inertially stabilized platform in the dynamic measurement of cold atomic gravimeter.

Dynamic gravity field measurement based on the cold atom absolute gravity measurement system has important applications in geological exploration, gravity field mapping and other fields. The inertial stabilized platform is the key component of the dynamic cold atom absolute gravity measurement system, which can isolate the interference of carrier angle motion and keep the atomic gravimeter probe in the horizontal attitude during the measurement process. In this paper, according to the dynamic measurement requirements of atomic gravimeter, a high-precision two-axis inertial stabilized platform system is designed. The relationship between attitude angle and gravity measurement error is analyzed, and the stability of the system is enhanced by lead-lag method. Then the static vertical vibration power spectrum of the platform is measured to consider its influence on dynamic gravity measurement. Finally, a dynamic gravity test experiment was conducted in the Yellow Sea to verify the attitude control accuracy of the platform, and the attitude data of the platform under different heading were evaluated. The attitude standard deviation of the platform was better than 4 × 10-5 rad, and the absolute gravity standard deviation of the linear round-trip measurement reached 1.49 mGal. The experimental data show that the inertial stabilized platform can meet the dynamic measurement requirements of the cold atom gravimeter.

Suppression of the SLC7A11/glutathione axis causes ferroptosis and apoptosis and alters the mitogen-activated protein kinase pathway in nasopharyngeal carcinoma.

SLC7A11 is a unit of the glutamate cystine antiporter Xc- system. It functions to import cystine for glutathione biosynthesis and maintains the redox balance in cells. Sorafenib inhibits the transporter activity of SLC7A11. The use of sorafenib has been approved in the treatment of multiple cancers. However, at present, our understanding of the mechanism of SLC7A11 and sorafenib in nasopharyngeal carcinoma (NPC) remains limited. We found that the expression of SLC7A11 was upregulated in NPC. A high SLC7A11 expression was associated with poor prognosis, metastasis, and an advanced T stage, which can be used as an independent prognostic indicator of NPC. In vitro, we observed that NPC cells relied on cystine for survival. Targeting SLC7A11 resulted in glutathione biosynthesis limitation, intracellular reactive oxygen species accumulation, lipid peroxides, ferroptosis, and apoptosis. Meanwhile, it altered mitogen activated protein kinase pathway, including p38 activation but ERK inhibition in NPC. This limited the proliferation of NPC cells. Sorafenib inhibited the proliferation and induced the death of NPC cells in vivo. In conclusion, SLC7A11 plays an important role in the occurrence and progression of NPC and may be a novel target for NPC treatment.

Pulsed arterial spin labeling effectively and dynamically observes changes in cerebral blood flow after mild traumatic brain injury.

Cerebral blood flow is strongly associated with brain function, and is the main symptom and diagnostic basis for a variety of encephalopathies. However, changes in cerebral blood flow after mild traumatic brain injury remain poorly understood. This study sought to observe changes in cerebral blood flow in different regions after mild traumatic brain injury using pulsed arterial spin labeling. Our results demonstrate maximal cerebral blood flow in gray matter and minimal in the white matter of patients with mild traumatic brain injury. At the acute and subacute stages, cerebral blood flow was reduced in the occipital lobe, parietal lobe, central region, subcutaneous region, and frontal lobe. Cerebral blood flow was restored at the chronic stage. At the acute, subacute, and chronic stages, changes in cerebral blood flow were not apparent in the insula. Cerebral blood flow in the temporal lobe and limbic lobe diminished at the acute and subacute stages, but was restored at the chronic stage. These findings suggest that pulsed arterial spin labeling can precisely measure cerebral blood flow in various brain regions, and may play a reference role in evaluating a patient's condition and judging prognosis after traumatic brain injury.

Pituitary metastasis of choriocarcinoma: A case report.

Choriocarcinoma is an aggressive obstetric or gynecological neoplasm with a high malignant potential. It is a form of gestational trophoblastic disease and often secondary to hydatidiform mole, and intrauterine or ectopic pregnancy. Choriocarcinoma has a proclivity to metastasize to the lung, vagina, pelvis or liver in over 50% of patients, which always occurs in the early stage of the disease. With an appropriate amount of chemotherapy, the tumor may be treated effectively. However, pituitary metastasis of choriocarcinoma is extremely rare. To the best of our knowledge, no cases of choriocarcinoma metastasizing to the pituitary have been cited previously. Here, we report a case of choriocarcinoma that presented with pituitary metastasis.

Identification of a new seven-span transmembrane protein: NGX6a is downregulated in nasopharyngeal carcinoma and is associated with tumor metastasis.

Nasopharyngeal carcinoma (NPC)-associated gene 6 (NGX6) is a novel candidate metastasis suppressor gene that can significantly decrease the growth, motility, and invasion of NPC cells. In this study, we generated a highly specific NGX6 polyclonal antibody and analyzed its distribution in the human fetus by Western blot and immunohistochemistry. The result of the Western blot showed the protein of NGX6 had two types of isoforms, isoform a (NGX6a) and isoform b (NGX6b). Isoform a is composed of 472 amino acids with a calculated molecular mass of 52 kDa, whereas isoform b is composed of 338 amino acids with a calculated molecular mass of 37 kDa. It is predicated that there is an epidermal growth factor domain in the N terminal of both a and b isoforms, and seven transmembrane domains in NGX6a, but only two transmembrane domains in NGX6b. The expression level of NGX6a was higher than that of NGX6b in human fetal tissue. Obvious high expression of NGX6a protein presents in the nervous system and epithelial tissues of the human fetus, but the NGX6b protein (37 kDa) is mainly expressed in the nervous system. We further analyzed the tissue microarray, which contained 154 NPC biopsies and 70 non-NPC biopsies, and found that NGX6a was significantly downregulated in NPC and associated with tumor metastasis.

Vascular basement membrane-derived multifunctional peptide, a novel inhibitor of angiogenesis and tumor growth.

Vascular basement membrane-derived multifunctional peptide (VBMDMP) gene (fusion gene of the human immunoglobulin G3 upper hinge region and two tumstatin-derived fragments) obtained by chemical synthesis was cloned into vector pUC19, and introduced into the expression vector pGEX-4T-1 to construct a prokaryotic expression vector pGEX-4T-1-VBMDMP. Recombinant VBMDMP produced in Escherichia coli has been shown to have significant activity of antitumor growth and antimetastasis in Lewis lung carcinoma transplanted into mouse C57Bl/6. In the present study, we have studied the ability of rVBMDMP to inhibit endothelial cell tube formation and proliferation, to induce apoptosis in vitro, and to suppress tumor growth in vivo. The experimental results showed that rVBMDMP potently inhibited proliferation of human endothelial (HUVEC-12) cells and human colon cancer (SW480) cells in vitro, with no inhibition of proliferation in Chinese hamster ovary (CHO-K1) cells. rVBMDMP also significantly inhibited human endothelial cell tube formation and suppressed tumor growth of SW480 cells in a mouse xenograft model. These results suggest that rVBMDMP is a powerful therapeutic agent for suppressing angiogenesis and tumor growth.

The role of NGX6 and its deletion mutants in the proliferation, adhesion and migration of nasopharyngeal carcinoma 5-8F cells.

OBJECTIVE: To demonstrate the subcellular localization of nasopharyngeal carcinoma (NPC)-associated gene 6 (NGX6) and its basic structure and function. METHODS: The deletion mutants of NGX6 were constructed by one-step PCR and transfected into NPC cell line 5-8F. The subcellular location of NGX6 or its mutants was detected by immunofluorescence staining of cytoplasm (CYTO) and nuclear protein, and immunoelectron-microscopic analysis. The role of NGX6 and its mutants in the proliferation, adhesion and migration of NPC 5-8F cells was detected using the following assays: growth curve, colony formation in soft agar, cell adhesion, in vitro Matrigel invasion, and in vitro scratch wound healing. RESULTS AND CONCLUSIONS: NGX6 and its mutants were distributed on the plasma membrane, nuclear membrane, endoplasmic reticulum membrane, and other membrane structures in the cytosol. The deleted domains did not affect its distribution in 5-8F cells. NGX6 could increase the adhesion but inhibited the proliferation, growth and migration of 5-8F cells. The epidermal growth factor-like domain and CYTO region were found to be important for NGX6 to modulate cell adhesion, and CYTO was found to be essential for NGX6 involved in the regulation of growth, proliferation, and migration of 5-8F cells.