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The fruit softening seriously affected the quality of Annona squamosa, and the edible coating combined with exogenous calcium had a positive effect on inhibiting the softening of A. squamosa. In this paper, the rheological properties of C-AeP-P solution and the effect of Ca2+ on the rheological properties of the solution were studied. Based on this, the indicators of fruit hardness, freshness and plumpness were used to monitor the softening effect of A. squamosa. The results show that: C-AeP-P solution showed non-Newtonian shear-thinning behavior over the range of 0.2-1.0%. With the increase of C-AeP-P concentration, the apparent viscosity and solids like properties increased. After the addition of Ca2+, C-AeP-P had apparent differences on apparent viscosity. The G′ and G″ of C-AeP-P were increased with increasing oscillation frequency. C-AeP-P and C-AeP-P+Ca2+ treatment can slow down rapidly decline of fruit hardness, increase of soluble solid content, loss of water, change peel color and regulate the expression of key enzyme genes AI and Ni. It was concluded that the coating treatment of C-AeP-P alleviates the adverse effects of quality changes during storage, so as to improve the quality and prolong the shelf life of A. squamosa.

Microcrystalline celluloses were isolated from four agricultural residues, including sweet sorghum stalk, Jerusalem artichoke stalk, grains stillage, and Chinese herb residue, and characterized in terms of physicochemical and structural properties. The obtained microcrystalline celluloses were composited with polylactic acid as a packing film for the preservation of Lanzhou lily. All the agricultural residues-derived microcrystalline celluloses were in cellulose I

At present, submersible electric pump is the main oil production equipment in the world’s oil fields. Because the pump is tested with clean water as the medium when it leaves the factory, it can not be widely used in all oil fields. In this paper, a prototype submersible electric pump is improved and designed according to the actual working conditions, and a new heavy oil pump is obtained, which can be widely used in heavy oil Wells. The static pressure distribution and velocity vector distribution under the actual working conditions were simulated by CFD, and the feasibility was verified. It provides theoretical basis and technical guidance for solving the adverse effect of high viscosity produced liquid on pump, and has certain guiding significance for oilfield pump selection. So as to effectively save electricity and rationally exploit energy.

The output of complementary energy is the core of power generation system planning, and researching its configuration is the basis for realizing safe, reliable, economical and stable operation of the system throughout total life cycle. This paper comprehensively considers the constraints of power supply reliability and battery energy storage operation, and proposes a capacity optimization method for wind-photovoltaic-hydro-storage system aiming at life cycle cost and unit cost of electricity. Take the Northwest Region as an example, the optimization problem was solved by HOMER software, the optimal capacity allocation result was obtained. Compared with other solutions, the life cycle cost was reduced by 12.1%, the unit cost of electricity was reduced by 11.9%, and the load power shortage rate probability was relatively reduced. The result prove that the complementary system helps to reduce power generation cost and improve power supply stability.

Background: Lung computed tomography (CT) image was considered assupplementary diagnostic criteria for COVID-19 in the newest diagnosis and treatment program; however, the diagnostic effectiveness of lung CT in patients that have a strict screening for symptoms, history and reverse transcription-polymerase chain reaction (RT-PCR) testing remain unclear. The purpose of this study was to share our experience about elective surgery during the COVID-19 pandemic and to analyze the effectiveness and necessity of lung CT for screening COVID-19 in elective surgery patients from low risk areas. Methods: Based on the database of our HospitalInformation System, all patients receiving elective surgery in departments of general surgery, hepatological surgery, orthopedics, neurosurgery and urology at our hospital from 11 January, 2020 to 11 May, 2020 were retrospectively involved. The general information, laboratory testing, comorbidities, reverse transcription-polymerase chain reaction (RT-PCR) and lung CT features were collected and analyzed. Findings: In total, 2375 patients (1150 females and 1225 males)were enrolled in this current study. The mean age was 52 years old, ranging from 6 to 94.All the RT-PCR results of these 2375 patients were negative, including the patients with fever. The most common features on lung CT were nodular lesions (n=624, 26.3%) and striplike lesions (n=467, 19.7%). While, there were only 120 patients (5.1%) with ground-glass opacities (GGO) and 54 patients (2.3%) with lung consolidations on the lung CT, which were ruled out the COVID-19 by the RT-PCR results, clinical manifestation, fever screen, contact history and travel history. During the hospital stay, a total number of 1085 patients were screened with temperature ≥ 37.3 ℃ ,which were ruled out COVID-19 by consultation of special fever clinic and respiratory department. Interpretation: After strict screening for symptoms, history (contact COVID-19 patients or travelling to high-risk areas) and RT-PCR testing, lung CT image was not recommended as routine examination in patients receiving selective surgery from the low-risk areas of COVID-19. Funding: This work was supported by grants from the Beijing Municipal Natural Science Foundation (No. 7192199), the Youth Support Project of Chinese PLA General Hospital (No. QNF19015) and the National Key Research and Development Program of China (No. 2020YFC2004900). Declaration of Interests: The authors declare no conflict of interest. Ethics Approval Statement: The study was approved by the Medical Ethics Committee of the Chinese PLA General Hospital and performed in accordance with the ethical standards in the 1964 Declaration of Helsinki.

Mitochondrial fission is important for the development and progression of pancreatic cancer (PC). However, little is known regarding its role in pancreatic cancer apoptosis, metabolism and migration. In the current study, the mechanism by which mitochondrial fission modifies the biological characteristics of PC was explored. MicroRNA‑125a (miR‑125a) had the ability to inhibit mitochondrial fission and contributed to cellular survival. Suppressed mitochondrial fission led to a reduction in mitochondrial debris, preserved the mitochondrial membrane potential, inhibited mitochondrial permeability transition pore opening, ablated cytochrome c leakage into the cytoplasm and reduced the pro‑apoptotic protein contents, finally blocking mitochondria related apoptosis pathways. Furthermore, defective mitochondrial fission induced by miR‑125a enhanced mitochondria‑dependent energy metabolism by promoting activity of electron transport chain complexes. Furthermore, suppressed mitochondrial fission also contributed to PANC‑1 cell migration by preserving the F‑actin balance. Furthermore, mitofusin 2 (Mfn2), the key defender of mitochondrial fission, is involved in inhibition of miR125a‑mediated mitochondrial fission. Low contents of miR‑125a upregulated Mfn2 transcription and expression, leading to inactivation of mitochondrial fission. Ultimately, the current study determined that miR‑125a and Mfn2 are regulated by hypoxia‑inducible factor 1 (HIF1). Knockdown of HIF1 reversed miR‑125a expression, and therefore, inhibited Mfn2 expression, leading to activation of mitochondrial fission. Collectively, the present study demonstrated mitochondrial fission as a tumor suppression process that is regulated by the HIF/miR‑125a/Mfn2 pathways, acting to restrict PANC‑1 cell survival, energy metabolism and migration, with potential implications for novel approaches for PC therapy.

We present a microfluidic rheometer that uses in situ pressure sensors to measure the viscosity of liquids at low Reynolds number. Viscosity is measured in a long, straight channel using a PDMS-based microfluidic device that consists of a channel layer and a sensing membrane integrated with an array of piezoresistive pressure sensors via plasma surface treatment. The micro-pressure sensor is fabricated using conductive particles/PDMS composites. The sensing membrane maps pressure differences at various locations within the channel in order to measure the fluid shear stress in situ at a prescribed shear rate to estimate the fluid viscosity. We find that the device is capable to measure the viscosity of both Newtonian and non-Newtonian fluids for shear rates up to 104 s−1 while keeping the Reynolds number well below 1.

We present a novel method of testing creep recovery in a microfluidic device. This method allows for the measurement of relaxation time of fluids at low strain. After applying a steady pressure-driven flow along a microchannel, the pressure is released and the fluid is allowed to relax and come to rest. Local strains are observed via the time-dependent velocity profiles and are fit to a general viscoelastic model to obtain the fluids' relaxation times. The use of polymeric solutions of various molecular weights allows for the observation of time scales for strains ranging from 0.01 to 10. Results are consistent with data obtained in a macroscopic rheometer and with a viscoelastic constitutive model.

We investigate the rheological characteristics of human blood plasma in shear and elongational flows. While we can confirm a Newtonian behavior in shear flow within experimental resolution, we find a viscoelastic behavior of blood plasma in the pure extensional flow of a capillary break-up rheometer. The influence of the viscoelasticity of blood plasma on capillary blood flow is tested in a microfluidic device with a contraction-expansion geometry. Differential pressure measurements revealed that the plasma has a pronounced flow resistance compared to that of pure water. Supplementary measurements indicate that the viscoelasticity of the plasma might even lead to viscoelastic instabilities under certain conditions. Our findings show that the viscoelastic properties of plasma should not be ignored in future studies on blood flow., Comment: 4 figures, 1 supplementary material Highlighted in http://physics.aps.org/articles/v6/18

In this paper, we present a microfluidic-based rheometer that uses in-situ pressure signals to measure the shear viscosity of liquids. The shear-viscosity is measured using a PDMS-based microfluidic device that consists of a channel layer and a sensing membrane integrated with an array of piezoresistive pressure sensors via plasma surface-treatment. The micro-pressure sensors are fabricated using conducting particles-PDMS composites, synthesized by mixing 82 wt% micrometer-sized silver particles (1–3 μm in diameter) with PDMS gels. The simple design and fabrication enable nearly perfect bonding of a 120 μm-thick sensing membrane to different channel geometries that map the pressure differences at various locations within the channel in order to measure the fluid shear stress in-situ and to estimate the fluid viscosity. Experimental validation of this microfluidic-based rheometer is performed using calibration oil of known viscosity as well as macroscopic rheometric data, both of which achieve good consistency. The present work allows in-situ measurements of rheological properties of fluids at low Re.

It is presently believed that flows of viscoelastic polymer solutions in geometries such as a straight pipe or channel are linearly stable. Here we present experimental evidence that such flows can be nonlinearly unstable and can exhibit a subcritical bifurcation. Velocimetry measurements are performed in a long, straight micro-channel; flow disturbances are introduced at the entrance of the channel system by placing a variable number of obstacles. Above a critical flow rate and a critical size of the perturbation, a sudden onset of large velocity fluctuations indicates presence of a nonlinear subcritical instability. Together with the previous observations of hydrodynamic instabilities in curved geometries, our results suggest that any flow of polymer solutions becomes unstable at sufficiently high flow rates., 5 pages, 4 figures