A Novel Model Considered Mass and Energy Conservation for Both Liquid and Vapor in Adsorption Refrigeration System.

In this paper, we proposed a dynamic model for a two-bed adsorption refrigeration system. Different from most existing researches which assume saturation vaper pressure in each device, the proposed method models the pressure in each device by considering both the liquid and vaper content in the device. Therefore, it can be more accurate in describing the system response and more suitable for studying the system instrumentation. The components included in this system model are: adsorption bed, evaporator, condenser, expansion valve, and etc. Each device is modeled based on the energy and mass conservation. Furthermore, the adsorption phenomenon is modeled by the “Freundlich equation,†and “linear driving force model.†The phase change of the refrigerant in evaporator and condenser is modeled by Hertz-Knudsen theory. In a case study, the pressure of the adsorption bed during the adsorption process is estimated to be 0.7kPa by the proposed model, while it was 1.6kPa by conventional method which assuming saturated vapor pressure. The coefficient-of-performance of the adsorption system is estimated to be 0.246 by this model, 0.36 by conventional method, and 0.28 by experimental data. The proposed model can estimate system performance more accurate than the conventional method. Moreover, the proposed model also inspire a new instrumentation strategy for the adsorption system, in which the system efficiency is improved and the pressure surge is avoided

The Conceptual Design of CubeSat Based System for GNSS Radio Occultation/Reflective Mission

The Global Navigation Satellite System (GNSS) Radio Occultation/Reflective (RO/R) instrument collects global atmospheric data and oceanic wind speed data for weather prediction and climate researches. This paper proposes the conceptual design of the satellite constellation and the satellite to realize the GNSS-RO/R mission based on the cubesat platform, with the goal to achieve cost effectiveness and minimum deployed schedule. The cubesat considered in the study is 6U and within 10 kilogram. The proposed innovative constellation consists of 12 (minimum required) plus 6 (backup) satellites on three 500 km altitude sun synchronous planes, 6 satellites even phasing on each plane. It is expected to have 3000 profile measurements per day at minimum (3600 profiles as a goal). The payload instrument will be able to collect RO/R measurements via GPS and GLONASS. The mission lifetime is 3 years. The on-orbit redundancy, instead of redundant satellite components, is adapted to increase system reliability. The satellite design of this study faces very tough challenging to meet the 10-kg mass constraint. The proposed solutions to lower down mass include the creative payload design, the plasma thruster based reaction control subsystem and attitude control subsystem, the use of special non-space grade made-in-Taiwan components, and the creative mission scheduling among satellites to optimize daily global coverage with limited duty cycle of each satellite (the duty cycle can not be 100% because of mass saving on solar array and battery). The study demonstrates the feasibility to achieve the system design. The lessons learned of the system design study have also been introduced. The international cooperation and investment to realize this development is welcome

Optimizing Clinical Utility of the Ultrasound-guided Core Biopsy for Head and Neck Tumor

BackgroundThe goal of this study is to validate the clinical utility and define the procedure setting of minimally invasive core biopsy that is performed under ultrasound guidance with small-gauge needles (USCB) in head and neck tumors.Materials and methodsA consecutive 56 patients with head and neck tumors received USCB with informed consents. Patients received USCB with different gauges of core needles randomly. The adequacy rate of the specimen and other clinical parameters were analyzed. The adequacy is defined as the target lesion is taken under ultrasound and specific diagnosis could be made by the specimen.ResultsThe overall diagnostic adequacy rate of USCB was 91%. Among different needle gauges of USCB, the 18-gauge group demonstrated a 100% adequate rate, a lower anesthetic demand (16.6%), and shorter postprocedure bleeding time (3.0 ± 1.4 minutes), showing significant differences when compared with others. No immediate or late complications were noted after procedure in all patients.ConclusionUSCB is minimally invasive and provides pathological information for diagnosis. It is a precise, safe, and office-based procedure and is suggested to be included in the diagnosis of head and neck tumors

Probing the Pore of ClC-0 by Substituted Cysteine Accessibility Method Using Methane Thiosulfonate Reagents

ClC channels are a family of protein molecules containing two ion-permeation pores. Although these transmembrane proteins are important for a variety of physiological functions, their molecular operations are only superficially understood. High-resolution X-ray crystallography techniques have recently revealed the structures of two bacterial ClC channels, but whether vertebrate ClC channel pores are similar to those of bacterial homologues is not clear. To study the pore architecture of the Torpedo ClC-0 channel, we employed the substituted-cysteine-accessibility method (SCAM) and used charged methane thiosulfonate (MTS) compounds to modify the introduced cysteine. Several conclusions were derived from this approach. First, the MTS modification pattern from Y512C to E526C in ClC-0, which corresponds to residues forming helix R in bacterial ClC channels, is indeed consistent with the suggested helical structure. Second, the ClC-0 pore is more accessible to the negatively charged than to the positively charged MTS compound, a pore property that is regulated by the intrinsic electrostatic potential in the pore. Finally, attempts to modify the introduced cysteine at positions intracellular to the selectivity filter did not result in larger MTS modification rates for the open-state channel, suggesting that the fast gate of ClC-0 cannot be located at a position intracellular to the Cl− selectivity filter. Thus, the proposal that the glutamate side chain is the fast gate of the channel is applicable to ClC-0, revealing a structural and functional conservation of ClC channels between bacterial and vertebrate species

Electrostatic Control and Chloride Regulation of the Fast Gating of ClC-0 Chloride Channels

The opening and closing of chloride (Cl−) channels in the ClC family are thought to tightly couple to ion permeation through the channel pore. In the prototype channel of the family, the ClC-0 channel from the Torpedo electric organ, the opening-closing of the pore in the millisecond time range known as “fast gating” is regulated by both external and internal Cl− ions. Although the external Cl− effect on the fast-gate opening has been extensively studied at a quantitative level, the internal Cl− regulation remains to be characterized. In this study, we examine the internal Cl− effects and the electrostatic controls of the fast-gating mechanism. While having little effect on the opening rate, raising [Cl−]i reduces the closing rate (or increases the open time) of the fast gate, with an apparent affinity of >1 M, a value very different from the one observed in the external Cl− regulation on the opening rate. Mutating charged residues in the pore also changes the fast-gating properties—the effects are more prominent on the closing rate than on the opening rate, a phenomenon similar to the effect of [Cl−]i on the fast gating. Thus, the alteration of fast-gate closing by charge mutations may come from a combination of two effects: a direct electrostatic interaction between the manipulated charge and the negatively charged glutamate gate and a repulsive force on the gate mediated by the permeant ion. Likewise, the regulations of internal Cl− on the fast gating may also be due to the competition of Cl− with the glutamate gate as well as the overall more negative potential brought to the pore by the binding of Cl−. In contrast, the opening rate of the fast gate is only minimally affected by manipulations of [Cl−]i and charges in the inner pore region. The very different nature of external and internal Cl− regulations on the fast gating thus may suggest that the opening and the closing of the fast gate are not microscopically reversible processes, but form a nonequilibrium cycle in the ClC-0 fast-gating mechanism

Ultrasonication-Assisted Spray Ionization Mass Spectrometry for the Analysis of Biomolecules in Solution

In this paper, we describe a novel technique—ultrasonication-assisted spray ionization (UASI)—for the generation of singly charged and multiply charged gas-phase ions of biomolecules (e.g., amino acids, peptides, and proteins) from solution; this method employs a low-frequency ultrasonicator (ca. 40 kHz) in place of the high electric field required for electrospray ionization. When a capillary inlet is immersed into a sample solution within a vial subjected to ultrasonication, the solution is continually directed to the capillary outlet as a result of ultrasonication-assisted capillary action; an ultrasonic spray of the sample solution is emitted at the outlet of the tapered capillary, leading to the ready generation of gas-phase ions. Using an ion trap mass spectrometer, we found that singly charged amino acid and multiply charged peptides/proteins ions were generated through this single-step operation, which is both straightforward and extremely simple to perform. The setup is uncomplicated: only a low-frequency ultrasonicator and a tapered capillary are required to perform UASI. The mass spectra of the multiply charged peptides and proteins obtained from sample solutions subjected to UASI resemble those observed in ESI mass spectra

Learning to See before Learning to Act: Visual Pre-training for Manipulation

Does having visual priors (e.g. the ability to detect objects) facilitate learning to perform vision-based manipulation (e.g. picking up objects)? We study this problem under the framework of transfer learning, where the model is first trained on a passive vision task, and adapted to perform an active manipulation task. We find that pre-training on vision tasks significantly improves generalization and sample efficiency for learning to manipulate objects. However, realizing these gains requires careful selection of which parts of the model to transfer. Our key insight is that outputs of standard vision models highly correlate with affordance maps commonly used in manipulation. Therefore, we explore directly transferring model parameters from vision networks to affordance prediction networks, and show that this can result in successful zero-shot adaptation, where a robot can pick up certain objects with zero robotic experience. With just a small amount of robotic experience, we can further fine-tune the affordance model to achieve better results. With just 10 minutes of suction experience or 1 hour of grasping experience, our method achieves ~80% success rate at picking up novel objects.Comment: Accepted to ICRA 2020. Porject page: http://yenchenlin.me/vision2action

Simultaneous Cranioplasty and Subdural-Peritoneal Shunting for Contralateral Symptomatic Subdural Hygroma following Decompressive Craniectomy

Background. Contralateral subdural hygroma caused by decompressive craniectomy tends to combine with external cerebral herniation, causing neurological deficits. Material and Methods. Nine patients who underwent one-stage, simultaneous cranioplasty and contralateral subdural-peritoneal shunting were included in this study. Clinical outcome was assessed by Glasgow Outcome Scale as well as Glasgow Coma Scale, muscle power scoring system, and complications. Results. Postoperative computed tomography scans demonstrated completely resolved subdural hygroma and reversed midline shifts, indicating excellent outcome. Among these 9 patients, 4 patients (44%) had improved GOS following the proposed surgery. Four out of 4 patients with lethargy became alert and orientated following surgical intervention. Muscle strength improved significantly 5 months after surgery in 7 out of 7 patients with weakness. Two out of 9 patients presented with drowsiness due to hydrocephalus at an average time of 65 days after surgery. Double gradient shunting is useful to eliminate the respective hydrocephalus and contralateral subdural hygroma. Conclusion. The described surgical technique is effective in treating symptomatic contralateral subdural hygroma following decompressive craniectomy and is associated with an excellent structural and functional outcome. However, subdural-peritoneal shunting plus cranioplasty thoroughly resolves the subdural hygroma collection, which might deteriorate the cerebrospinal fluid circulation, leading to hydrocephalus