Electrocardiogram Parameters Associated With the Diagnosis of Pulmonary Hypertension in High-Altitude Tibetan Populations: A Retrospective Single-Centre Study.

BACKGROUND: Electrocardiogram (ECG) is a commonly used diagnostic method for pulmonary hypertension (PH) in Tibetan areas, but its sensitivity and specificity are not good enough. This study aimed to investigate the ECG parameters associated with the diagnosis of PH in Tibetan areas. METHODS: Ninety-four PH patients of Tibetan ethnicity who were treated at the hospital between March 2019 and October 2020, and 52 Tibetan individuals as controls, were included. The ECG parameters were compared between groups. Multivariate logistic analysis was performed to identify the ECG parameters that can be used for the diagnosis of PH. The univariate significances of ECG parameters were included in the multivariate analyses, whereas those exhibiting opposite trends between different PH subtypes were excluded. RESULTS: Two ECG parameters were significant in multivariate analysis. The final model included S wave amplitude in lead V3 (OR 5.81; 95% CI 2.79-12.11; p<0.001) and a negative T wave in leads V1-V3 (OR 0.05; 95% CI 0.01-0.41; p=0.005). The ROC curve analysis on the final model yielded an AUC of 0.830 (95% CI 0.766-0.894; p<0.001), indicating good diagnostic performance. A nomogram for diagnosis of PH was also established using S wave amplitude in lead V3 and a negative T wave in leads V1-V3. CONCLUSION: The ECG parameters S wave amplitude in lead V3 and a negative T wave in leads V1-V3 were independent factors associated with the diagnosis of PH in high-altitude Tibetan populations.

Observation of the curative effect of intraocular lens in patients with cataract and establishment of the intraocular lens database.

BACKGROUND: Intraocular lenses are widely used in the treatment of cataract patients, but currently clinical, procedural and product information is incomplete in many hospitals and there is an urgent need for a database to improve surgical safety, and outcomes. METHODS: Data on the brand and specifications of the intraocular lens, and the postoperative outcome of cataract patients after intraocular lens implantation from January 2017 to June 2018 were collected to create an intraocular lens database as an online public platform. RESULTS: A total of 96 cataract patients were divided into groups A and B based on preoperative corrected visual acuity. At 3 months after surgery the visual acuity of patients in group A recovered from 1.51±0.19 to 0.76±0.18, and the in group B it recovered from 1.02±0.27 to 0.49±0.13. Overall, the postoperative visual acuity of all patients improved significantly (P<0.001). We also used the NEI-VFQ-25 visual function questionnaire to evaluate the visual function of the patients before and after surgery. At 3 months after surgery, the mean score of patients in group A increased from 21.89±14.21 to 59.97±18.29 and in group B it increased from 38.26±17.57 to 70.28±12.37. Overall, the patients' postoperative scores increased significantly (P<0.001). CONCLUSIONS: Cataract phacoemulsification and intraocular lens implantation can effectively and safely restore and improve the visual function of cataract patients. Information sharing through establishment of an intraocular lens information database will assist in further advances and consistency in the treatment of cataract patients.

Meniscus Shape and Wetting Competition of a Drop between a Cone and a Plane.

The formation of a liquid bridge between a cone and a plane is related to dip-pen nanolithography. The meniscus shape and rupture process of a liquid meniscus between a cone and a plane are investigated by Surface Evolver, many-body dissipative particle dynamics, and macroscopic experiments. Dependent on the cone geometry, cone-plane separation, and wetting properties of cone and plane, three types of menisci can be observed before rupture and two types of wetting competition outcomes are seen after breakup. It is interesting to find that after rupture, the bulk of the liquid bridge volume is not necessarily retained by the cone which is more wettable. In fact, a sharp hydrophilic cone often loses wetting competition to a hydrophobic plane. To explain our findings, the "apparent" contact angle of the cone is introduced and the behavior of drop-on-cone/plane system is analogous to that of a liquid bridge between two parallel planes based on this concept.

Ultralow voltage irreversible electrowetting dynamics of an aqueous drop on a stainless steel surface.

The electrowetting dynamics of a water drop on a stainless steel surface in air is investigated under ultralow voltages. The spreading behavior can be classified into three regimes. The drop expands slowly in regime I, but the spreading accelerates quite rapidly in regime II. The spreading becomes insignificant in regime III. The experimental results are compared to the equilibrium shapes acquired by Surface Evolver simulations. The good agreement between them indicates that the slow electrowetting dynamics can be considered to be a quasi-equilibrium process. The influences of the electric field and drop size on the spreading dynamics are examined. The variation of both the contact angle and base diameter with time in regimes II and III can be well described by the exponential change with a characteristic time, which grows with the drop volume but is inversely proportional to the electric field. A simple model based on the electromechnical mechanism is proposed to explain the spreading dynamics. The exponential change is attributed to ion migration from the bulk of the drop to the contact line. The experimental results agree well with the prediction of our simple theory.

Drops on hydrophilic conical fibers: gravity effect and coexistent states.

Controlling the droplet equilibrium location and shape on a conical fiber is essential to industrial applications such as dip-pen nanolithography. In this work, the equilibrium conformations of a drop on a vertical, conical fiber has been investigated by the finite element method, Surface Evolver simulations. Similar to the morphology of a drop on a cylinder, two different types (barrel shape and clam-shell shape) can be obtained. In the absence of gravity, the droplet moves upward (lower curvature) and the total surface energy decays as the drop ascends. Whatever the initial conformation of the drop on a conical fiber, the rising drop exhibits the clam-shell shape eventually and there is no equilibrium location. However, in the presence of gravity, the drop can stop at the equilibrium location stably. For a given contact angle, the clam-shell shape is generally favored for smaller drops but the barrel shape is dominant for larger drops. In a certain range of drop volume, the coexistence of both barrel and clam-shell shapes is observed. For large enough drops, the falling-off state is seen.

Equilibrium phase diagram of drop-on-fiber: coexistent states and gravity effect.

Drop-on-fiber is commonly observed in daily life and is closely related to digital microfluidics. The wetting behavior of droplet-on-fiber is different from that of droplet-on-plane due to the global cylindrical shape. It is generally believed that the equilibrium geometric shape of a droplet on a fiber takes either asymmetric clam-shell or axisymmetric barrel conformation in the absence of gravity. The barrel-to-clam-shell transition is determined by the stability condition. Nonetheless, experimental observations showed that both barrel and clam-shell conformations can coexist in some situations and thus indicated the existence of the multiple stable states. In this Article, the phase diagrams of droplet-on-fiber, that is, the plots of droplet volume against contact angle, are established on the basis of the finite-element simulation (Surface Evolver). When the gravity effect is absent, there are three regimes including barrel, clam-shell, and coexistence of barrel and clam-shell. As the gravity effect is considered, there exist three regimes, including (I) downward clam-shell, (II) coexistence of barrel and clam-shell, and (III) falling-off.