The Mechanosensitive Piezo1 Channel Mediates Mechanochemical Transmission in Myopic Eyes.

Purpose: To identify the expression of the mechanosensitive ion channel Piezo1 in the retina of guinea pigs with form deprivation myopia (FDM) and to investigate mechanisms by which Piezo1 channels might regulate myopia. Method: Sixty 3-week-old guinea pigs were divided into four groups randomly: normal control, FDM, FDM + vehicle control (DMSO), and FDM + Piezo1 inhibitor (GsMTx4). Measurements of spherical equivalent (SE) and axial length (AL) of the guinea pig were taken using retinoscopy and A-scan ultrasound examination, respectively. Location of Piezo1 protein was determined using immunohistochemistry. The histological structure and thickness changes of the guinea pig retina were observed by hematoxylin and eosin. Expression of Piezo1 in the retina was detected using quantitative RT-PCR and Western blot. Reactive oxygen species (ROS) levels in the retina were measured using flow cytometry. Result: After 4 weeks of form deprivation, the FDM group exhibited a significantly increased myopic degree and axial length compared with the normal control group (all P < 0.001), and had higher expression levels of Piezo1 and ROS than the normal control group (P < 0.001 and P = 0.002, respectively). Piezo1 protein expression was down-regulated in guinea pigs given GsMTx4 compared with the DMSO group (P = 0.037). Additionally, the GsMTx4 group showed lower myopic degree (P < 0.001) and lower ROS levels (P = 0.019) compared with the DMSO group. Conclusions: The Piezo1 channel may be activated in the retinas of FDM guinea pigs and be involved in the development of myopia by regulating intraocular ROS levels.

Research on line loss analysis and intelligent diagnosis of abnormal causes in distribution networks: artificial intelligence based method.

The primary source of energy losses in distribution networks (DNs) is rooted in line losses, which is crucial to conduct a thorough and reasonable examination of any unusual sources of line losses to guarantee the power supply in a timely and safe manner. In recent studies, identifying and analyzing abnormal line losses in DNs has been a widely and challenging research subject. This article investigates a key technology for the line loss analyses of DNs and intelligent diagnosis of abnormal causes by implementing artificial intelligence (AI), resulting in several prominent results. The proposed algorithm optimizes the parameters of the support vector machine (SVM) and suggests an intelligent diagnosis algorithm called the Improved Sparrow Search Algorithm and Support Vector Machine (ISSA-SVM). The ISSA-SVM algorithm is trained to calculate the data anomalies of line losses when changing loads and exhibiting exceptional performance to identify abnormal line losses. The accuracy of abnormality identification employing the ISSA-SVM algorithm reaches an impressive 98%, surpassing the performances of other available algorithms. Moreover, the practical performance of the proposed approach for analyzing large volumes of abnormal line loss data daily in DNs is also noteworthy. The ISSA-SVM accurately identifies the root causes of abnormal line losses and lowers the error in calculating abnormal line loss data. By combining different types of power operation data and creating a multidimensional feature traceability model, the study successfully determines the factors contributing to abnormal line losses. The relationship between transformers and voltage among various lines is determined by using the Pearson correlation, which provides valuable insights into the relationship between these variables and line losses. The algorithm's reliability and its potential to be applied to real-world scenarios bring an opportunity to improve the efficiency and safety of power supply systems. The ISSA that incorporates advanced techniques such as the Sobol sequence, golden sine algorithm, and Gaussian difference mutation appears to be a promising tool.

Expression of SCO1 and SCO2 after form-deprivation myopia in Guinea pigs.

PURPOSE: The retina is a highly energy-consuming tissue associated with visual development, and the reduced quality of retinal imaging can be related to myopia. Synthesis of cytochrome c oxidase 1 (SCO1) and synthesis of cytochrome c oxidase 2 (SCO2) are involved in ATP (adenosine triphosphate) synthesis and energy metabolism. This study aimed to observe the morphologic changes and investigate the expression of SCO1 and SCO2 induced by form-deprivation myopia (FDM) in the retina and sclera of guinea pigs. METHODS: Thirty-six 3-week-old male guinea pigs were randomly assigned to one of two groups: (1) the model group (n = 18), in which the right eyes were covered by a thin opaque balloon as FDM group, and the left eyes were uncovered and served as the contralateral control group; (2) the blank control group (n = 18), in which bilateral eye received no manipulation. Eyeballs were enucleated for histological analysis. The retina and sclera of the guinea pigs were separated to determine the protein and mRNA expression levels of SCO1 and SCO2, respectively. RESULTS: After four weeks of form deprivation (FD), the refractive degree and axial length increased significantly (P < 0.001). The retinal and scleral tissues were moderately thinner, and the ganglion cells and the cells of inner and outer nuclear layers in the retina became fewer. Compared with the contralateral control group (P < 0.001) and the blank control group (P < 0.001), the collagen content of the sclera became less in the FDM group. The protein and mRNA expression levels of SCO1 and SCO2 in the FDM group were significantly lower than those in the contralateral control group and the blank control group (P < 0.05). CONCLUSIONS: The morphologies of the retina and sclera were changed, and the expression of SCO1 and SCO2 at the protein and transcription levels was significantly reduced in the FDM group. Given these changes, SCO1 and SCO2 genes may be involved in myopic progression.

Timely identification of atypical acute aortic dissection in the emergency department:a study from a tertiary hospital

Background/aim: Acute aortic dissection (AAD) is a rare but fatal disease if left untreated. Symptoms are often similar to common conditions; therefore, the diagnostic strategy is important. We aimed to identify the atypical symptoms in a timely manner without putting patients at greater risk for undetected AAD. Materials and methods: We conducted a retrospective observational study of 59 AAD patients with both atypical and typical symptoms from January 2012 to December 2016. Patients with atypical symptoms continuing more than 30 min underwent a D-dimer test and computed tomography (CT) or computed tomographic angiography (CTA). Results: Of the 59 AAD patients, 22 were atypical. In the atypical group, the median delay time in our hospital was 3.1 h; average delay time after July 2015 was shorter than average delay time before June 2015 (16.59 ± 24.70 vs. 1.90 ± 0.57 h, P = 0.076). Conclusions: For patients in the emergency department who are suspected of having AAD, incorporating atypical symptoms with high levels of D-dimer into a triage strategy could improve the efficiency of clinical decision making. Furthermore, essential education directed towards the recognition of the atypical symptoms of AAD for front-line physicians may aid in a timely diagnosis, as compared with the usual assessments in the emergency department.

Activity and Transcriptional Responses of Hepatopancreatic Biotransformation and Antioxidant Enzymes in the Oriental River Prawn Macrobrachium nipponense Exposed to Microcystin-LR.

Microcystins (MCs) are a major group of cyanotoxins with side effects in many organisms; thus, compounds in this group are recognized as potent stressors and health hazards in aquatic ecosystems. In order to assess the toxicity of MCs and detoxification mechanism of freshwater shrimp Macrobrachium nipponense, the full-length cDNAs of the glutathione S-transferase (gst) and catalase (cat) genes were isolated from the hepatopancreas. The transcription level and activity changes in the biotransformation enzyme (glutathione S-transferase (GST)) and antioxidant enzymes (superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx)) in the hepatopancreas of M. nipponense exposed to MC-LR (0.2, 1, 5, and 25 µg/L) for 12, 24, 72 and 96 h were analyzed. The results showed that the isolated full-length cDNAs of cat and gst genes from M. nipponense displayed a high similarity to other crustaceans, and their mRNAs were mainly expressed in the hepatopancreas. MC-LR caused significant increase of GST activity following 48-96 h (p < 0.05) and an increase in SOD activity especially in 24- and 48-h exposures. CAT activity was activated when exposed to MC-LR in 12-, 24- and 48-h exposures and then it was inhibited at 96-h exposure. There was no significant effect on GPx activity after the 12- and 24-h exposures, whereas it was significantly stimulated after the 72- and 96-h exposures (p < 0.05). The transcription was altered similarly to enzyme activity, but the transcriptional response was generally more immediate and had greater amplitude than enzymatic response, particularly for GST. All of the results suggested that MC-LR can induce antioxidative modulation variations in M. nipponense hepatopancreas in order to eliminate oxidative damage.

Physiological responses of astronaut candidates to simulated +Gx orbital emergency re-entry.

INTRODUCTION: We investigated astronaut candidates' physiological and pathological responses to +Gx exposure during simulated emergency return from a running orbit to advance astronaut +Gx tolerance training and medical support in manned spaceflight. METHODS: There were 13 male astronaut candidates who were exposed to a simulated high +Gx acceleration profile in a spacecraft during an emergency return lasting for 230 s. The peak value was 8.5 G. Subjective feelings and symptoms, cardiovascular and respiratory responses, and changes in urine component before, during, and after +Gx exposure were investigated. RESULTS: Under high +Gx exposure, 15.4% of subjects exhibited arrhythmia. Heart rate (HR) increased significantly and four different types of HR response curves were distinguished. The ratio of QT to RR interval on the electrocardiograms was significantly increased. Arterial oxygen saturation (SaO2) declined with increasing G value and then returned gradually. SaO2 reached a minimum (87.7%) at 3 G during the decline phase of the +Gx curve. Respiratory rate increased significantly with increasing G value, while the amplitude and area of the respiratory waves were significantly reduced. The overshoot appeared immediately after +Gx exposure. A few subjects suffered from slight injuries, including positive urine protein (1/13), positive urinary occult blood (1/13), and a large area of petechiae on the back (1/13). CONCLUSIONS: Astronaut candidates have relatively good tolerance to the +Gx profile during a simulation of spacecraft emergent ballistic re-entry. However, a few subjects exhibited adverse physiological responses and slight reversible pathological injuries.

Scaling of critical connectivity of mobile ad hoc networks.

In this paper, critical global connectivity of mobile ad hoc networks (MANETs) is investigated. We model the two-dimensional plane on which nodes move randomly with a triangular lattice. Demanding the best communication of the network, we account the global connectivity eta as a function of occupancy sigma of sites in the lattice by mobile nodes. Critical phenomena of the connectivity for different transmission ranges r are revealed by numerical simulations, and these results fit well to the analysis based on the assumption of homogeneous mixing. Scaling behavior of the connectivity is found as eta approximately f(R;{beta}sigma) , where R=(r-r_{0})r_{0} , r_{0} is the length unit of the triangular lattice, and beta is the scaling index in the universal function f(x) . The model serves as a sort of geometric distance-dependent site percolation on dynamic complex networks. Moreover, near each critical sigma_{c}(r) corresponding to certain transmission range r , there exists a cutoff degree k_{c} below which the clustering coefficient of such self-organized networks keeps a constant while the averaged nearest-neighbor degree exhibits a unique linear variation with the degree k , which may be useful to the designation of real MANETs.

[Preventive study of vocal scar after fiber laryngoscope surgery].

OBJECTIVE: To explore the importance and preventive measure of vocal scar after fiber laryngoscope surgery. METHOD: The preventive measures such as treatment of the pathogeny, voice exercise, adjustment of operative skill, vocal rest after operation and drug treatment for vocal scars in 350 patients with polyps of vocal cord, vocal nodules and vocal cyst after fiber laryngoscope surgery were adopted in order to reduce the rate of vocal scar. The rate of vocal scar was calculated and analysed to evaluate the effect of preventive measures two month later. RESULT: The incidence rate of vocal scar after fiber laryngoscope surgery was 12.3%. And vocal scar was the main difficulty in vocalizing after operation. There is yet no specific treatment for vocal scar. Prevention is more important. Preventive measures should be carried out through the perioperative period, i. e., before, in and after the surgery. CONCLUSION: The prevention of vocal scar complication is very important in the perioperative period of fiber laryngoscope surgery. And as the preventive measures are adopted, the incidence rate of vocal scar will be significantly reduced.

Universal scaling behavior of clustering coefficient induced by deactivation mechanism.

We propose a model of network growth that generalizes the deactivation model previously suggested for complex networks. Several topological features of this generalized model, such as the degree distribution and clustering coefficient, have been investigated analytically and by simulations. A scaling behavior of clustering coefficient C approximately 1/M is theoretically obtained, where M refers to the number of active nodes in the network. We discuss the relationship between the recently observed numerical behavior of clustering coefficient in the coauthor and paper citation networks and our theoretical result. It shows that both of them are induced by deactivation mechanism. By introducing a perturbation, the generated network undergoes a transition from large to small world, meanwhile the scaling behavior of C is conserved. It indicates that C approximately 1/M is a universal scaling behavior induced by deactivation mechanism.

[The application of three dimensional analysis system in measuring rotation angles of thumb carpometacarpal joints].

OBJECTIVE: To measure the axial rotation angles of the carpometacarpal joints during the digital opposition of thumb-index finger, thumb-medial finger, thumb-ring finger, thumb-little finger and the thumb's maximal opposition, then the application of these parameters were studied. METHODS: Twenty neutrality-occupation volunteers (female 10, male 10) with no history of hand injuries or related diseases were involved in the study. First, all the markers' 3-D coordinates were obstained using the 3D motion analysis system (EVaRT4.1) during the digital opposition movements of thumb. Then, the axial rotation angles were calculated. RESULTS: The average rotation angles of carpometacarpal joints during all kinds of digital oppositions were 29.1 degrees +/- 9.4 degrees (male), 24.8 degrees +/- 10.2 degrees (female), while the maximal rotation angles are: 35.3 degrees (male), 28.8 degrees (female). CONCLUSIONS: The combination of video-based 3-D analysis system and mathematics make it possible to measure the axial rotation angles of thumb in vivo, as a result, the rotation angles of thumb carpometacarpal joints are measured precisely for the first time. These results can provide a few parameters for treatment and rehabilitation of carpometacarpal arthrositis.

The human TAZ gene complements mitochondrial dysfunction in the yeast taz1Delta mutant. Implications for Barth syndrome.

Barth syndrome is a genetic disorder that is caused by different mutations in the TAZ gene G4.5. The yeast gene TAZ1 is highly homologous to human TAZ, and the taz1Delta mutant has phospholipid defects similar to those observed in Barth syndrome cells, including aberrant cardiolipin species and decreased cardiolipin levels. Subcellular fractionation studies revealed that Taz1p is localized exclusively in mitochondria, which supports the theory that tafazzins are involved in cardiolipin remodeling. Because cardiolipin plays an important role in respiratory function, we measured the energy transformation and osmotic properties of isolated mitochondria from the taz1Delta mutant. Energy coupling in taz1Delta mitochondria was dependent on the rate of oxidative phosphorylation, as coupling was diminished when NADH was used as a respiratory substrate but was unaffected when ethanol was the substrate. Membrane stability was compromised in taz1Delta mitochondria exposed to increased temperature and hypotonic conditions. Mitochondria from taz1Delta also displayed decreased swelling in response to ATP, which induces the yeast mitochondrial unspecific channel, and to alamethicin, a membrane-disrupting agent. Coupling was measured in taz1Delta cells containing different splice variants of the human TAZ gene. Only the variant that restores wild type cardiolipin synthesis (lacking exon 5) restored coupling in hypotonic conditions and at elevated temperature. These findings may shed light on the mitochondrial deficiencies observed in Barth syndrome.

Aberrant cardiolipin metabolism in the yeast taz1 mutant: a model for Barth syndrome.

In eukaryotic cells, the acyl species of the phospholipid cardiolipin (CL) are more highly unsaturated than those of the other membrane phospholipids. Defective acylation of CL with unsaturated fatty acids and decreased total CL are associated with Barth syndrome, an X-linked cardio- and skeletal myopathy attributed to a defect in the gene G4.5 (also known as tafazzin). We constructed a yeast mutant (taz1) containing a null mutation in the homologue of the human G4.5 gene. The yeast taz1Delta mutant was temperature sensitive for growth in ethanol as sole carbon source, but grew normally on glucose or glycerol plus ethanol. Total CL content was reduced in the taz1Delta mutant, and monolyso-CL accumulated. The predominant CL acyl species found in wild-type cells, C18:1 and C16:1, were markedly reduced in the mutant, whereas CL molecules containing saturated fatty acids were present. Interestingly, CL synthesis increased in the mutant, whereas expression of the CL structural genes CRD1 and PGS1 did not, suggesting that de novo biosynthetic enzyme activities are regulated by CL acylation. These results indicate that the taz1Delta mutant is an excellent genetic tool for the study of CL remodelling and may serve as a model system for the study of Barth syndrome.

The determination of the free energy of an electrical double layer.

A well-known charging process is used to obtain the free energy of an electrical double layer, in which the double layer is built up by a transfer of ions from one phase to another. The present study formulates proofs that this charging process cannot determine the free energy of an electrical double layer.