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• A ventilation strategy for prevention and control of COVID-19 was investigated. • Interactive cascade ventilation can cope with the adverse effects of thermal buoyancy. • Interactive cascade ventilation enhances contaminant removal efficiency by 1.1∼1.78 times. • Interactive cascade ventilation reduces the infection risk by 5 %∼22.1 % within 4 h. The ventilation system plays a key role in maintaining a healthy environment in an enclosed space. To seek a reasonable air distribution method and improve indoor air quality, the air change efficiency, exposure risk and infection risk under heating conditions are explored in a comparative experimental study under ICV, stratum ventilation (SV) and mixing ventilation (MV). The results demonstrate that with the same amount of air (94 l/s) and designed room temperature (22 °C), the air change efficiency of ICV is 9.8 % and 24.3 % higher than SV and MV, indicating the excellent ability to form a clean and healthy breathing layer. During the pandemic, ICV can reduce the infection risk of COVID-19 by 5 % and 22.1 % in four hours relative to SV and MV. Exposure risk distribution research results demonstrate that ICV can maintain a reduction in exposure level of 9.64–44.44 % even at a location farther from the air inlet and provide a safer environment where people sit frequently. The conclusions obtained in this study can provide a new approach for ventilation to address COVID-19 and indoor air quality problems during heating season. [ABSTRACT FROM AUTHOR]

Abstract The pond wolf spider, Pardosa pseudoannulata , is one of the most dominant predators of several agriculture insect pests including mainly the rice planthoppers and leafhoppers in paddy fields in Asia. Venom has been an attractive subject as the powerful weapon of spiders due to the complex components secreted from venom gland. The transcriptome of P. pseudoannulata venom gland was sequenced in order to understand the diversity of venom components at the molecular level and provide a new perspective for insect pest management. A total of 48 potential peptide toxins were identified from 75,980 assembled transcripts. Among them, 32 putative neurotoxin precursors were classified into six families systematically. In addition to neurotoxins, peptide toxins with potential antiviral and antifungal activities were annotated as well as the protease inhibitors. The diversity of P. pseudoannulata venom was firmly demonstrated with the presence of astacin-like metalloprotease toxins, Kunitz-type serine protease inhibitors, venom allergen 5, hyaluronidase and other important venom components. In addition, the tissue expression profiles of the toxin-related genes were investigated in venom gland, brain, and fat body. The present study classified the diverse venom components P. pseudoannulata and provided essential information of potential insecticidal toxins for the biological control of insect pests. [ABSTRACT FROM AUTHOR]

Bladder outlet obstruction (BOO) can cause serious complications including kidney damage; nevertheless, there are currently no animal models for studying BOO-induced kidney damage. Mesenchymal stem cells (MSCs) are widely used in therapeutic studies of renal fibrosis. However, MSC-derived exosomes show improved safety profile and more controllable characteristics compared with those of MSCs. Herein, we established a kidney injury mouse model of partial bladder outlet obstruction (PBOO) and evaluated the effects of human umbilical cord MSC-derived exosomes (hucMSC-Exos) on PBOO-induced reflux kidney injury in this model. Exosomes were isolated from a hucMSC-conditioned medium, purified by ultracentrifugation, and examined. Living image was performed to indicate the distribution of hucMSC-Exos. The PBOO-treated mice interacted with PBS (phosphate-buffered saline) or hucMSC-Exos. Morphologic changes and expression of interstitial-fibrosis—related, cell proliferation and Wnt/β-catenin signaling-pathway indices were evaluated. At 7 days after induction of PBOO, structural destruction of renal tubules was observed. Expression of the interstitial markers and the cellular-proliferation index increased significantly in the PBOO group compared with the control group. The isolated exosomes were 30–150 nm in diameter, showing a round shape and bilayer membrane structure with CD63, TSG101, Alix expressed, enriched in the kidney of the PBOO group. Administering hucMSC-Exos to post-PBOO mice reversed renal injury and suppressed expression of Wnt/β-catenin signaling pathway-related proteins. hucMSC-Exos inhibited PBOO-induced kidney injury and cellular proliferation and suppressed the Wnt/β-catenin signaling pathway. Our findings will spur the development of novel hucMSC-Exo-mediated therapies for treating patients with renal fibrosis. [ABSTRACT FROM AUTHOR]

Seeking an energy-saving and healthy heating system is significant to realize carbon neutrality and enhance thermal comfort. In this paper, the performance of a novel ventilation mode named interactive cascade ventilation (ICV) for space heating was carried out. Stratum ventilation (SV) and mixing ventilation (MV) were selected as the reference ventilation modes. Objective and visualized experiments were employed to investigate the thermal and energy performance of the three ventilation modes. The results demonstrated that when reducing the heating capacity supply by 13.9%, the overall temperature of ICV is 4.5% and 27.9% higher than SV and MV, respectively. The comparison results of local temperature rising ratio and temperature response time demonstrated that ICV showed the most substantial ability to control the local environment and the highest energy utilization efficiency. In addition, compared with SV, ICV reduced the head draft rate by 44.8% and 24% when sitting and standing, obviously improving thermal performance. The conclusion obtained from this research can cast a new light on the space heating system. • Heating performance of interactive cascade ventilation was studied by experiments. • Interactive cascade ventilation elevates the occupied zone temperature by 8%–36.8%. • Interactive cascade ventilation can reduce the head draft rate by 24%–44.8%. • Interactive cascade ventilation can reduce the temperature responds time by 18.5%–33.3%. [ABSTRACT FROM AUTHOR]

In the era of Corona Virus Disease 2019 (COVID-19), inappropriate indoor ventilation may turn out to be the culprit of microbial contamination in enclosed spaces and deteriorate the environment. To collaboratively improve the thermal comfort, air quality and virus spread control effect, it was essential to have an overall understanding of different ventilation modes. Hence, this study reviewed the latest scientific literature on indoor ventilation modes and manuals of various countries, identified characteristics of different ventilation modes and evaluated effects in different application occasions, wherefore to further propose their main limitations and solutions in the epidemic era. For thermal comfort, various non-uniform ventilation modes could decrease the floor-to-ceiling temperature difference, draft rate or PPD by 60%, 80% or 33% respectively, or increase the PMV by 45%. Unsteady ventilation modes (including intermittent ventilation and pulsating ventilation) could lower PPD values by 12%–37.8%. While for air quality and virus spread control, non-uniform ventilation modes could lower the mean age of air or contaminants concentration by 28.3%–47% or 15%–47% respectively, increase the air change efficiency, contaminant removal effectiveness or protection efficiency by 6.6%–10.4%, 22.6% or 14%–50% respectively. Unsteady ventilation mode (pulsating ventilation) could reduce the peak pollutant concentration and exposure time to undesirable concentrations by 31% and 48% respectively. Non-uniform modes and unsteady modes presented better performance in thermal comfort, air quality and virus spread control, whereas relevant performance evaluation indexes were still imperfect and the application scenarios were also limited. [ABSTRACT FROM AUTHOR]

Calommata signata , a burrowing spider, represents a special type of predation mode in spiders, and its utilization of toxins is different from that of web-weaving spiders and wandering spiders. The existing researches on spider toxins are mainly focused on the web-weaving and wandering spiders, but little attention on that of the burrowing spiders. Through transcriptome sequencing of C. signata venom gland and the remaining part as the counterpart tissue, 25 putative neurotoxin precursors were identified. These most neurotoxins were novel because their low similarities with the known sequences except for that of over 50% similarities in four neuropeptide toxins. The 25 neuropeptide toxins were divided into five families according to the constitution of cysteines for the possible disulfide bonds and the similarities of the deduced amino acid sequences. Besides neuropeptide toxins, other potential toxins in the venom gland were also analyzed. Unlike web-weaving spiders and wandering spiders, only a few neurotoxin genes were significantly expressed in the venom gland of C. signata. In the non-peptide toxin genes, only CsTryp_SPc-1, CsPA2–1, CsVa5–2 and four PDI genes were abundantly expressed in the venom gland. The present study provided an improved understanding on the spider toxin diversity and useful information for the exploitation of spider toxins. [Display omitted] • Twenty-five putative neurotoxin precursors were identified in Calommata signata venom glands. • The few number of cysteines in neurotoxins of C. signata have simple arrangements. • Few neurotoxin genes were highly expressed in the venom glands of C. signata. [ABSTRACT FROM AUTHOR]

The interaction between linearly polarized elliptical hollow beam and a two-level atom is investigated theoretically. Although the linearly polarized elliptical hollow beam does not carry angular momentum, it can produce very high torque. The atoms initially at rest and located at off-beam-axis positions will rotate under the drive of the torque of the beam. The shorter the distance from the original location of atom to the axis is, the larger the average angular frequency of atom rotation is. The average angular frequency can reach as high as 1000 Hz. This convinces us that the elliptical hollow beam might be a useful tool in the study of quantum property of Bose–Einstein condensate or ultra cold atom media. [Copyright &y& Elsevier]

Abstract The coherence of cold atom trapped and cooled by the partially coherent light (PCL) is investigated experimentally through Rabi oscillations. We control the degree of the spatial coherence of the laser beams by the modulation of electro-optic crystal. The experimental results show that the cold atoms captured by the different coherent degree of light have little different coherence properties and almost the same capacity of resisting disturbance, which indicates that the coherence of cold atom is affected weakly by the coherence of cooling field. [ABSTRACT FROM AUTHOR]

Although mixed land use is an important way to improve land-use efficiency and stimulate socioeconomic vitality, there are few systematic analyses of mixed land use in rural settlements. This paper proposes the connotation and measurements of mixed land use in rural settlements, considering both land-use diversity and compatibility. Case studies of Tangwei village (a tourist village), Guxia village (a commercial village), and Fulong village (an industrial village) in Dongguan City, Pearl River Delta, China, are chosen to analyze the characteristics of mixed land use in different types of rural settlements using field research, POI data capture, GIS, and remote sensing techniques. The results indicate that: (1) In 1978, 2005, and 2020, the degree of mixed land use in the rural settlement of Tangwei village was 0.68, 0.84, and 0.96, respectively, reflecting an increase of 41.17%; in Guxia village, it was 0.69, 0.86, and 0.84, respectively, growing and then declining, yielding a total increase of 21.73%; in Fulong village, it was 0.74, 0.82, and 0.89, respectively, reflecting an increase of 20.27%. (2) In 1978, 2005, and 2020, the land-use diversity of Tangwei village was 0.44, 0.94, and 0.92, respectively, representing a 109% improvement; land-use compatibility was 0.68, 0.72, and 0.96, respectively, with an increase of 41.17%. The land-use diversity of Guxia village was 0.46, 0.76, and 0.78, respectively, with an increase of 69.57%; land-use compatibility climbed by 24.64% from 0.69 to 1 to 0.84. The land-use diversity of Fulong village was 0.53, 0.83, and 0.88, respectively, which increased by 66.03%; land-use compatibility was 0.74, 0.81, and 0.89, respectively, which increased by 20.27%. (3) The mixed land use of Tangwei village is primarily influenced by policy support, resource endowment, and industrial foundation. The primary drivers of Guxia village are policy support, geographic location, and industrial foundation. Policy support, resource endowment, and industrial foundation are the most critical factors in Fulong village. Ultimately, land-use diversity and compatibility determine the mixed land use of rural settlements. This study offers suggestions for village planning, rural industrial development, and enhancing the living environment in China. • A conceptual framework of mixed land use in rural settlements was established. • The characteristics and driving forces of mixed land-use evolution in rural settlements were revealed. • Considering land-use diversity and compatibility improved the measurement of mixed land use. • Mixed land use of rural settlements can promote the coordinated improvement of villagers' living conditions and rural industrial development. [ABSTRACT FROM AUTHOR]

• Multiple RF photon resonance transition is observed with strong RF couple regime. • Based on the Flquet perturbation theory, the analytical expression for multi-RF photon resonance frequency is presented. • Numerical simulation based on Liouville equation reproduces the experimental features. The multiple radio frequency (RF) photon transitions of optical magnetic resonance of 133 Cs atoms are demonstrated theoretically and experimentally. In the presence of a static magnetic field with a fixed direction, the atomic resonance absorption signals irradiated by a circularly polarized light are observed under the condition of different intensities and directions of RF field in our experiment. We find that both the RF intensity and direction can modify the character of the observed signals. If the RF intensity is strong enough, when the RF field is perpendicular to the static magnetic field, only odd number RF photon resonance transitions can be observed. When the RF field is parallel to the static field, no resonance occurs in the experiment. However, if it is between the two cases, all positive integer resonance transitions will be recorded completely. Furthermore, both the analytical solution based on Floquet perturbation theory and the numerical simulation based on Liouville equation strongly support the experimental results. These phenomena enable us to reveal the optical magnetic resonance dynamics more deeply. [ABSTRACT FROM AUTHOR]

Carbon nanofibers (CNFs) and carbon nanotubes (CNTs), which have been known for decades, recently gained significant commercial interests for various applications. However, the controlled synthesis of CNF/CNT has been hindered by the lack of nanoscale experimental evidence on how the growth temperature affects the growth process under real growth environment. We report the in situ transmission electron microscopy (TEM) experiments to directly observe Ni catalyzed CNF/CNT growth from alcohol precursor at near atmospheric pressure using a homebuilt bubbler system for the introduction of ethanol vapor. Using real time imaging, we revealed the active state of the Ni catalyst during the temperature-dependent CNF/CNT growth (600–800 °C). We observed the formation of CNFs starting from 600 °C and CNTs were formed at higher temperatures. The lattice parameter measurements pointed to an expansion of the Ni lattice as the temperature was increased, which we attribute to increased carbon solubility. The as-grown CNFs and CNTs were further characterized by XPS, Raman spectroscopy, and EELS, that allowed to have a highly reliable overall view of the structure changes with temperature. Results revealed that the change in structure with temperature was caused by the combined effects of increased carbon solubility and graphitization of the walls of the growing nanostructure. This increased carbon solubility in turn affected carbon diffusion and could be the reason for the change in structure from CNF to CNT at high temperature. Using in situ TEM we clearly revealed the effect of growth temperature on the structural changes. [Display omitted] • Direct observation of temperature dependent growth of CNF/CNT from ethanol vapor. • Structural change mechanism was determined by SAED and spectroscopic studies. • SAED showed the presence of Ni carbide active phase during the growth. • Spectroscopic studies (EELS/XPS/Raman) proved temperature-dependent graphitization. • Activation energy calculation suggested carbon diffusion path for CNF/CNT growth. [ABSTRACT FROM AUTHOR]

Increasing low-grade and renewable energy sources in the HVAC systems has become necessary to reduce heating energy consumption. Hence, seeking a new air conditioning system that can be combined with renewable energy is significant to maintain a healthy and comfortable indoor environment with a low cost. This paper proposes a novel air source heat pumps assisted solar hot water with interactive cascade ventilation system (shortened as SWAP-ICV). Taking the traditional air source heat pumps with mixing ventilation system (AP-MV) as a reference, the virus control performance and energy efficiency of SWAP-ICV is investigated through CFD and TRNSYS simulations. The results demonstrate that interactive cascade ventilation under full-fresh air operation mode and normal-epidemic linkage mode can make the annual infection risk reduce by 41.16% and 9.33% compared with mixing ventilation under full-fresh air operation mode. Meanwhile, the proposed system can reduce energy consumption by 59.92% and 69.8% during the normal period and epidemic period by introducing solar energy. The average system COP during the heating season indicates that SWAP-ICV can improve the system efficiency by 1.9–2.58 times than AP-MV system. The conclusions obtained from this research can provide new ideas for the design and operation of air conditioning systems in the post-epidemic era. • A novel interactive cascade ventilation (SWAP-ICV) system was established. • Normal-epidemic linkage operation mode of SWAP-ICV was proposed. • The SWAP-ICV system can make the annual infection risk reduce by 41.16% and 9.33%. • The new operation mode can reduce energy consumption by 69.8%. • The SWAP-ICV system can improve COP by 1.9–2.58 times during the heating season. [ABSTRACT FROM AUTHOR]

Unmanned underwater vehicles (UUVs) cooperative localization technology has become an emerging research topic, which can extend the space-time datum of satellite navigation to seafloor, and provide high-precision location for UUVs to carry out large-area marine environment investigation, exploration and search. Nevertheless, the complex underwater environment makes it impossible to avoid the abnormal condition for sensor fault and outliers. In this contribution, a novel resilient model of multi-UUVs cooperative localization is established. The three-dimensional system model and measurement model are constructed based on the inertial navigation system, and the deviation between multi-sensors are defined and corrected. Furthermore, the resilient factor is proposed based on the normalized prediction residual, and the resilient fusion of UUVs cooperative localization is realized by three steps, i.e., (1) Dynamic resilient fusion of single UUV; (2) Static resilient fusion of single UUV; (3) Static resilient fusion of UUVs cluster. In order to verify the effectiveness of the proposed resilient model, the sound velocity profile in the Nankai trough is selected. The experimental results show that the proposed resilient model of UUVs cooperative localization can accurately detect the abnormal observations and significantly improve the reliability of UUVs cooperative localization. • A novel resilient model of multi-UUVs cooperative localization is established. • The three-dimensional system model and measurement model are constructed. • The resilient factor is proposed based on the normalized prediction residual. • The proposed model can accurately detect the abnormal observations. [ABSTRACT FROM AUTHOR]

International Simple Glass – a six oxide borosilicate glass selected by the international nuclear glass community to improve the understanding of glass corrosion mechanisms and kinetics – was altered at 90 °C in a solution initially saturated with respect to amorphous 29 SiO 2 . The pH 90°C , was fixed at 9 at the start of the experiment and raised to 11.5 after 209 d by the addition of KOH. Isotope sensitive analytical techniques were used to analyze the solution and altered glass samples, helping to understand the driving forces and rate limiting processes controlling long-term glass alteration. At pH 9, the corrosion rate continuously drops and the glass slowly transforms into a uniform, homogeneous amorphous alteration layer. The mechanisms responsible for this transformation are water penetration through the growing alteration layer and ion exchange. We demonstrate that this amorphous alteration layer is not a precipitate resulting from the hydrolysis of the silicate network; it is mostly inherited from the glass structure from which the most weakly bonded cations (Na, Ca and B) have been released. At pH 11.5, the alteration process is very different: the high solubility of glass network formers (Si, Al, Zr) triggers the rapid and complete dissolution of the glass (dissolution becomes congruent) and precipitation of amorphous and crystalline phases. Unlike at pH 9 where glass corrosion rate decreased by 3 orders of magnitude likely due to the retroaction of the alteration layer on water dynamics/reactivity at the reaction front, the rate at pH 11.5 is maintained at a value close to the forward rate due to both the hydrolysis of the silicate network promoted by OH − and the precipitation of CSH and zeolites. This study provides key information for a unified model for glass dissolution. [ABSTRACT FROM AUTHOR]

• Dual frequency transient signal is observed for the first time with RF field. • Experimental values of the RF detuning and intensity agree well with the theoretical parameters. • Angular momentum probability surface explains all the features. The transient evolution of optical-magnetic resonance of 133 Cs atoms with the action of a radio-frequency (RF) field in the presence of a static magnetic field is demonstrated theoretically and experimentally. The atomic transient absorption signal irradiated by a linearly polarized light is observed for different frequencies and intensities of RF field in our experiment. We find that both the RF frequency and intensity can modify the character of the observed signals. In particular, with an intermediate intensity, when the frequency of the RF field does not match the Larmor precession caused by the static magnetic field, a two-frequency oscillation of the transient signal can be observed. However, for the resonant case or large detuning, the transient oscillation signals go back to single frequency. Theoretical analysis based on the simplified four-level density-matrix formalism strongly supports the presented experimental data. Moreover, the density-matrix visualization analysis based on angular momentum probability surface (AMPS) explains and confirms all the features of the experimental results. These quantifiable observations enable us to reveal the atomic transient evolution more intuitively. [ABSTRACT FROM AUTHOR]