Coverage Planning for UVC Irradiation: Robot Surface Disinfection Based on Swarm Intelligence Algorithm.

Ultraviolet (UV) radiation has been widely utilized as a disinfection strategy to effectively eliminate various pathogens. The disinfection task achieves complete coverage of object surfaces by planning the motion trajectory of autonomous mobile robots and the UVC irradiation strategy. This introduces an additional layer of complexity to path planning, as every point on the surface of the object must receive a certain dose of irradiation. Nevertheless, the considerable dosage required for virus inactivation often leads to substantial energy consumption and dose redundancy in disinfection tasks, presenting challenges for the implementation of robots in large-scale environments. Optimizing energy consumption of light sources has become a primary concern in disinfection planning, particularly in large-scale settings. Addressing the inefficiencies associated with dosage redundancy, this study proposes a dose coverage planning framework, utilizing MOPSO to solve the multi-objective optimization model for planning UVC dose coverage. Diverging from conventional path planning methodologies, our approach prioritizes the intrinsic characteristics of dose accumulation, integrating a UVC light efficiency factor to mitigate dose redundancy with the aim of reducing energy expenditure and enhancing the efficiency of robotic disinfection. Empirical trials conducted with autonomous disinfecting robots in real-world settings have corroborated the efficacy of this model in deactivating viruses.

UFO-Net: A Linear Attention-Based Network for Point Cloud Classification.

Three-dimensional point cloud classification tasks have been a hot topic in recent years. Most existing point cloud processing frameworks lack context-aware features due to the deficiency of sufficient local feature extraction information. Therefore, we designed an augmented sampling and grouping module to efficiently obtain fine-grained features from the original point cloud. In particular, this method strengthens the domain near each centroid and makes reasonable use of the local mean and global standard deviation to extract point cloud's local and global features. In addition to this, inspired by the transformer structure UFO-ViT in 2D vision tasks, we first tried to use a linearly normalized attention mechanism in point cloud processing tasks, investigating a novel transformer-based point cloud classification architecture UFO-Net. An effective local feature learning module was adopted as a bridging technique to connect different feature extraction modules. Importantly, UFO-Net employs multiple stacked blocks to better capture feature representation of the point cloud. Extensive ablation experiments on public datasets show that this method outperforms other state-of-the-art methods. For instance, our network performed with 93.7% overall accuracy on the ModelNet40 dataset, which is 0.5% higher than PCT. Our network also achieved 83.8% overall accuracy on the ScanObjectNN dataset, which is 3.8% better than PCT.

Carrier-Free, Pure Nanodrug Formed by the Self-Assembly of an Anticancer Drug for Cancer Immune Therapy.

Ursolic acid (UA) is a food-plant-derived natural product which has good anticancer activities and low toxicity. However, the poor water solubility of UA limits its application in clinic. To address this issue, we developed a carrier-free nanodrug by self-assembly of UA. Here, we showed that UA nanoparticles (NPs) have a near-spherical shape with a diameter of ∼150 nm. UA NPs exhibited higher antiproliferative activity; significantly caused apoptosis; decreased the expression of COX-2/VEGFR2/VEGFA; and increased the immunostimulatory activity of TNF-α, IL-6, and IFN-ß and decreased the activity of STAT-3 in A549 cells in vitro. Furthermore, UA NPs could inhibit tumor growth and have the ability of liver protection in vivo. More importantly, UA NPs could significantly improve the activation of CD4+ T-cells, which indicated that UA NPs have the potential for immunotherapy. Overall, a carrier-free UA nanodrug may be a promising drug to further enhance their anticancer efficacy and immune function.

An in vivo quantitative Raman-pH sensor of arterial blood based on laser trapping of erythrocytes.

We report on a continuous and non-invasive approach in vivo to monitor arterial blood pH based on the laser trapping and Raman detection of single live erythrocytes. A home-built confocal laser tweezers Raman system (LTRS) is applied to trace the live erythrocytes at different pH values of the extracellular environment to record their corresponding Raman changes in vitro and in vivo. The analysis results in vitro show that when the extracellular environment pH changes from 6.5 to 9.0, the Raman intensity ratio (R1603, 1616 = I1603/I1616) of single erythrocytes decrease regularly; what is more, there is a good linear relationship between these two variables, and the linearity is 0.985, which is also verified successfully via in vivo Raman measurements. These results demonstrate that the Raman signal of single live erythrocytes is possible as a marker of the extracellular pH value. This in vivo and quantitative Raman-pH sensor of arterial blood will be an important candidate for monitoring the acid-base status during the treatment of ill patients and in some major surgeries because of its continuous and non-invasive characters.

Feasibility analysis of inactivating influenza A(H1N1) virus using UVC robot in classroom environment.

Background: Starting from 2009, H1N1 has been one of the respiratory diseases that afflict the global population. Concurrently, due to the influence of COVID-19, it has become widely accepted that preventing the virus's spread necessitates personal protection measures and disinfection in public spaces. Experiments: This study conducted two experiments. In the classroom experiment, six UVC dose test points were calibrated to test whether the UVC dose at each testing point met the standards for inactivating IAVs and the time required to meet the standards. In the simulated classroom experiment, seven square slides made of IAVs were placed. After 10 min of robot movement, irradiated sterile square slides were made into suspension and injected into chicken embryos. Cultivate chicken embryos and conduct IAVs testing. Results: Classroom experiment has shown that 5 testing points can meet the standards for inactivating IAVs(3 mJ/cm2), with a required time of 80 min, 40 min, 15 min, 5 min and 10 min. The UVC dose for testing points that do not meet the standards in 80 min is only 0.5 mJ/cm2. The simulation classroom experiment outcomes revealed that 99.99 % of IAVs were deactivated. Furthermore, this study established both a desktop control group and a chair arm control group, both of which yielded identical results, indicating an inactivation logarithm of IAVs≥4log. Conclusion: The study presented that IAVs on the surface of an object can be effectively and rapidly deactivated at an irradiation density of 1.8 mW/cm2. Meanwhile, the study provides evidence of the feasibility of using the GXU robot to inactivate IAVs in a classroom environment.

Performance Optimization of Pb0.97La0.03Sc0.45Ta0.45Ti0.1O3 Ceramics by Annealing Process.

The annealing effects on Pb0.97La0.03Sc0.45Ta0.45Ti0.1O3 (PLSTT) ceramics prepared by the solid-state reaction method are systemically investigated using experimental and theoretical techniques. Comprehensive studies are performed on the PLSTT samples by varying annealing time (AT) from t (=0, 10, 20, 30, 40, 50 and 60) h. The properties involving ferroelectric polarization (FP), electrocaloric (EC) effect, energy harvesting performance (EHP) and energy storage performance (ESP) are reported, compared and contrasted. All these features are seen to gradually improve with the increase in AT, and they all reach the climaxed-shaped values and then decrease by further increasing the AT. For t = 40 h, the maximum FP (23.2 µC/cm2) is attained at an electric field of 50 kV/cm, while the high EHP effects (0.297 J/cm3) and positive EC are achieved (for ΔT~0.92 K and ΔS~0.92 J/(K·kg)) at 45 kV/cm. The EHP value of the PLSTT ceramics increased by 21.7% while the polarization value was enhanced by 33.3%. At t = 30 h, the ceramics have attained the best ESP value of 0.468 J/cm3 with an energy loss of 0.05 J/cm3. We strongly believe that the AT plays a crucial role in the optimization of different traits of the PLSTT ceramics.

Mitochondrial DNA polymorphisms are associated with the longevity in the Guangxi Bama population of China.

Human longevity is an interesting and complicated subject, with many associated variations, geographic and genetic, including some known mitochondrial variations. The population of the Bama County of Guangxi Province of China is well known for its longevity and serves as a good model for studying a potential molecular mechanism. In this study, a full sequence analysis of mitochondrial DNA (mtDNA) has been done in ten Bama centenarians using direct sequencing. Polymorphisms of the displacement loop (D-loop) region of mtDNA and several serum parameters were analyzed for a total of 313 Bama individuals with ages between 10 and 110 years. The results showed that there were seven mitochondrial variations, A73G, A263G, A2076G, A8860G, G11719A, C14766T, and A15326G, and four haplogroups, M(*), F1, D* and D(4) in 10 Bama centenarians. In the D-loop region of mtDNA, the mt146T occurred at a significantly lower frequency in those is the older age group (90-110 years) than in the middle (80-89 years) and in the younger (10-79 years) groups (P < 0.05). The mt146T also had lower systolic blood pressure and serum markers such as total cholesterol, triglyceride and low density lipoprotein than did mt146C in the older age group (P < 0.05). No significant differences were observed between the mt146C and the mt146T individuals in the middle and the younger groups (P > 0.05). The mt5178C/A polymorphisms did not show any significant differences among the three age-groups (P > 0.05), but different nationalities in the Bama County did show a significant difference in the mt5178C/A polymorphisms (P < 0.05). These results suggest that the mt146T/C polymorphisms in Guangxi Bama individuals may partly account for the Bama longevity whereas the mt5178C/A polymorphisms are strongly associated with the nationalities in the Guangxi Bama population.

0.5 m Triboelectric Nanogenerator for Efficient Blue Energy Harvesting of All-Sea Areas.

Triboelectric nanogenerators (TENGs) to harvest ocean wave blue energy is flourishing, yet the research horizon has been limited to centimeter-level TENG. Here, for the first time, a TENG shell is advanced for ocean energy harvesting to 0.5 m and an excellent frictional areal density of 1.03 cm-1 and economies of scale are obtained. The unique structure of the multi-arch shape is adopted to untie the difficulty of fully getting the extensive friction layer contact. An inside steel plate is vertically placed in the center of every TENG block, which can activate the TENG to achieve complete contact even at a tilt angle of 7 degrees. The proposed half-meter TENG (HM-TENG) has a broad response band from 0.1 to 2 Hz, a total transferred charge quantity up to 67.2 µC, and one single TENG can deliver an open-circuit voltage of 368 V. Coupled with the self-stabilizing and susceptible features the ellipsoid shell brings, the HM-TENG can readily accommodate itself to the all-weather, all-sea wave energy harvesting. Muchmore, the HM-TENG is also applied to RF signal transmitters. This work takes the first step toward near-meter-scale enclosures and provides a new direction for large-scale wave energy harvesting.

The First-Principle Study on Tuning Optical Properties of MA2Z4 by Cr Replacement of Mo Atoms in MoSi2N4.

Recently, with the successful preparation of MoSi2N4, an emerging family of two-dimensional (2D) layered materials has been predicted with a general formula of MA2Z4 (M: an early transition metal, A: Si or Ge and Z: N, P, or As). In terms of this new type of 2D material, how to effectively tune its light absorption properties is unclear. We systematically discuss the effects of replacing Mo with Cr atoms on the lattice structure, energy bands, and light absorption properties of 2D monolayer MoSi2N4 using density functional theory (DFT) and the Vienna Ab initio Simulation Package (VASP). Additionally, the results show that the single replacement of the atom Cr has no significant effect on the lattice structure of the outermost and sub-outer layers but plays a major role in the accumulation of electrons. In addition, the 2D MoSi2N4, Mo0.5Cr0.5Si2N4, and CrSi2N4 all have effective electron-hole separation properties. In the visible region, as the excited state increases, the required excitation energy is higher and the corresponding wavelength of light is shorter. It was found that the ultraviolet (UV)-visible spectra are red-shifted when Cr atoms replace Mo atoms in MoSi2N4; when Cr atoms and Mo atoms coexist, the coupling between Cr atoms and Mo atoms achieves modulation of the ultraviolet (UV)-visible spectra. Finally, we reveal that doping M-site atoms can effectively tune the light absorption properties of MA2Z4 materials. These results provide a strategy for the design of new 2D materials with high absorption properties.

Factors Affecting Surface Plasmon Coupling of Quantum Wells in Nitride-Based LEDs: A Review of the Recent Advances.

Surface plasmon (SP)-enhanced quantum-well (QW) LEDs have proved their potential in replacing conventional lighting devices for their high-performance capabilities in ultraviolet (UV), blue and green spectral ranges. The SP-enhanced QW-LEDs have applications in light emission enhancement, light polarization, color conversion, and speed modulation. The electric field of the plasmonic mode of a metal couples with the exciton energy of QWs in resonance results in efficiency enhancement to several folds. The strength of the SP-QW coupling is mainly influenced by the type of metal used for SP enhancement, the metal nanostructure geometry, and the penetration depth of the SP fringing field in the p-GaN. The use of an appropriate dielectric interlayer between the metal and the p-GaN allows further control over SP resonance with QW emission wavelength. The penetration depth defines the p-GaN thickness and the QW period number for effective SP-QW coupling. The optimization of these parameters is key to achieve high efficiencies in SP-enhanced QW-LEDs for various applications. This review explains the SP enhancement mechanism and the key challenges facing the SP enhancement of QW-LEDs. The main factors that affect the SP-QW coupling have been explained in detail based on recent reports devoted to this field.

Dielectric and energy storage properties of Bi2O3-B2O3-SiO2 doped Ba0.85Ca0.15Zr0.1Ti0.9O3 lead-free glass-ceramics.

A sol-gel method is employed for preparing high quality lead-free glass-ceramic samples (1 - x)BCZT-xBBS-incorporating Ba0.85Ca0.15Zr0.1Ti0.9O3 (BCZT) powder and Bi2O3-B2O3-SiO2 (BBS) glass-doped additives with different values of x (x = 0, 0.05, 0.1, 0.15). Systematic investigations are performed to comprehend the structural, dielectric and energy storage characteristics using X-ray diffraction, field-emission scanning electron microscopy, impedance and ferroelectric analyser methods. With appropriate BBS doping (x), many fundamental traits including breakdown strength, dielectric loss and energy storage density have shown significant improvements. Low doping-level samples x < 0.1 have retained the pure perovskite phase while a second glass phase appeared in samples with x ≥ 0.1. As the doping level (0.1 ≥ x > 0) is increased, the average grain size decreased to become better homogeneous materials with improved breakdown energy strengths. Excessive addition of BBS (x = 0.15) causes negative effects on microstructures and other traits. The glass-ceramic sample 0.95BCZT-0.05BBS exhibits excellent dielectric permittivity and temperature stability, with the highest energy storage density of 0.3907 J cm-3 at 130 kV cm-1. These results provide good reference to develop lead-free ceramics of high energy storage density.

[Laser tweezers Raman spectroscopy analysis of liver cancer tissue].

Single cell laser tweezers Raman spectroscopy (LTRS) has been applied to biology field. In the present article, the authors measured the spectra of liver cancer cells, para-cancer cells and normal hepatocytes using single cell laser tweezer Raman spectroscopy (LTRS) system and compared their average spectra changes. The results showed that the laser tweezers Raman spectroscopy could differentiate specimens of different pathological changes from liver tissue studied. The 1 070 and 1 266 cm(-1) peaks obtained from normal hepatocytes were more visible than the same two peaks obtained from liver cancer and para-cancer specimen. The 1 445 cm(-1) peak of normal hepatocytes was higher than that of liver cancer cells and para-cancer cells. It is known that the 1 070 cm(-1) peak represents lipids and nucleic acids, while 1 266 and 1 445 cm(-1) peaks represent lipids and proteins. So, these peak changes may directly reflect the changed biomaterials related to liver carcinogenesis. Thus, single cell laser tweezer Raman spectroscopy may be a nondestructive, rapid and good method to measure and analyze different pathological specimens from liver cancer.

[The effect of abnormal cell shape on the spectral distinguishing of erythrocytes using laser tweezers Raman spectroscopy].

Erythrocyte is a mature blood cell that contains hemoglobin to carry oxygen to the bodily tissues. Erythrocyte, which takes on a biconcave disc that has no nucleus, is flexible and changeful. Erythrocyte is so sensitive to the environment that the shape of cell goes crimpy, even acanthoid. A laser tweezers Raman spectroscopy (LTRS) setup was used to trap single erythrocyte from healthy donors and patients with thalassemia and to collect the Raman scattering of trapping cell. Normal shape, crimpy erythrocytes and acanthoid erythrocytes were tested, and the averaged spectra, and principal component analysis (PCA) which detailed the spectral difference and the change of hemoglobin, were used to evaluate the effects of different cell shape on the spectral distinguishing of erythrocyte. The results reveal that in normal physiological environment the change in cell shape does not effect the spectral distinguishing of abnormal erythrocyte.

[Using Raman spectroscopy to analyze apoptosis of gastric cancer cells induced by cisplatin].

Apoptosis of gastric cancer cells induced by cisplatin was investigated using laser Raman spectroscopy. Gastric cancer cells (SGC7901) were treated with 10 microg x mL(-1) cisplatin for 24, 48 and 72 hours, then were divided into two parts, one for fluorescence staining, the other for collection of Raman spectra by means of scanning. The acquired spectra were then preprocessed by background elimination, smoothing, normalization, baseline correction, and peak fitting. Fluorescence staining result showed that the nucleuses from untreated group were uniformly stained, while those from the group treated for 72 hours were densely stained and broken. The spectra results revealed that the intensity of peaks associated with nucleic acid and protein decreased after the cells were incubated with cisplatin for 24, 48 and 72 hours. The intensity of peaks at 783, 1002 and 1343 cm(-1) respectively fell to 52, 64 and 76 percent of the original value after 72 h of treatment, which indicated that cisplatin could induce apoptosis of gastric cancer cells and reduce the amount of nucleic acid and protein in the cells. The above results suggest that Raman spectra can provide abundant information about the changes in materials in cells and serve as an effective method for real time measurement of apoptosis.

A Novel Universal Approach for Temperature Correction on Frequency Domain Spectroscopy Curve of Transformer Polymer Insulation.

It is a fact that the frequency domain spectroscopy (FDS) curve at different temperatures can be corrected by the shift factor (αT) extracted from the master curve. However, the αT and master curve reported by previous works are distinctive due to the difference in the construction algorithm. Therefore, it is of great significance to report a universal approach for extracting αT. In this work, the unaged oil-immersed pressboards with different moisture content (mc%) are firstly prepared and selected as the research specimen. Then, the αT of FDS curves on the above pressboard is extracted based upon the master curve technique. The influence mechanism under the various test temperature (T) and mc% is therefore analyzed so as to establish a universal model for predicting the αT. The present findings reveal that the αT value extracted from FDS curves is both temperature-dependent and moisture-dependent. In addition, the predicted αT is not only suitable for temperature correction on FDS curve of same type pressboard with different insulation conditions (moisture contents and aging degrees), but also maintains considerable accuracy when applied to different types of pressboard. Therefore, the obtained conclusions will provide a universal method for temperature correction on FDS curve of transformer polymer insulation.

NIR Raman spectroscopic investigation of single mitochondria trapped by optical tweezers.

Raman spectroscopy is a vibration spectroscopic technique that has been widely used to probe biochemical changes of biological sample such as tumor tissue, blood cells, bacteria and yeast. Here, we applied near-infrared Raman spectroscopy to analyze the chemical composition changes of intact or swollen mitochondria induced by calcium ions. We used a confocal Laser Tweezers Raman Spectroscopy (LTRS) system that combined optical trapping and near infrared Raman spectroscopy to confine a single mitochondrion and consequently measure its Raman spectra following the addition of calcium ion solution. We analyzed Raman spectra of mitochondria isolated from rat liver, heart muscle and kidney, respectively. The major Raman peaks at 1654, 1602, 1446, 1301 and 1226 cm(-1) were observed from individual intact mitochondria. We examined the differences in near infrared spectra between intact and Ca(2+) damaged mitochondria. We found that after the exposure of the intact mitochondria to the 100 muM Ca(2+) solution the band of 1602 cm(-1) decreased very rapidly in the first period and then disappeared after 30minutes, while the intensities of the phospholipids and protein bands changed slowly in the first period and then suddenly disappeared, corresponding to the Ca(2+) induced swelling process. These results demonstrate the potential of LTRS technique as a valuable tool for the study of bioactivity and molecular composition of mitochondria.

[Raman micro-spectroscopy of single blood platelets].

The authors collected the Raman spectra of single blood platelets of human, pig, rat and rabbit suspended in saline so-lution by using a laser tweezers Raman spectroscopy (LTRS) setup. A single platelet cell was trapped in the focus of a near-infrared laser beam at 785 nm and the excited Raman spectrum was acquired. For each species, the Raman spectra of up to 20 platelet cells were acquired and were used to perform a principal components analysis (PCA) or a discriminate function analysis (DFA). The average Raman spectra indicate that the vibration bands at 1 524 and 1 157 cm(-1) of human platelets are obviously different from those of the platelets from pig, rat and rabbit. The Raman intensities at 1 157 and 1 524 cm(-1) bands are significantly high for human platelets. The ratio I1 157 / I1 003 of human platelets was 0.795, but those of pig, rat and rabbit were 0.532, 0.502 and 0.485, respectively. In addition, the platelets from four different species can be discriminated with multivariate analysis. These findings demonstrate that the LTRS, combined with multivariate analysis, could be used to rapidly discriminate platelets from various species and may find valuable application in rapid sensing of biochemical changes in a single cell.

[Study of Raman spectra of single carcinoma of nasopharynx cell].

The Raman spectra from carcinoma of nasopharynx cell lines (CNE2) and normal airway epithelial cell lines (HBE) were investigated using a laser tweezers Raman spectroscopy (LTRS). The Raman scattering measurements were obtained from three different places in every single cell. Visual inspection of the spectra shows that the differences observed in spectra of the cancer cells and normal cells are obvious. The peak ratio I1 304/I1 336 is 1.05 for the normal cell and 1.22 for the cancer cell. Using a combination of principal component analysis (PCA) and discriminant function analysis (DFA), the authors are able to predict cancer cells, and normal cells and the DFA is better for single Raman spectrum. The sampling locations did not seriously affect the result of PCA and DFA. PCA and DFA also show that the uniformity of normal cells is better than that of cancer cells. The results indicate that the Raman spectra may offer the experimental basis for colorectal cancer diagnosis.

[Study of Raman spectroscopy of optically trapped human red blood cell affected by direct current].

Laser tweezers Raman spectroscopy (LTRS) system is a combination of spectroscopy and laser tweezers; It is a new method of studying cells; It can trap single living cell and make Raman spectrum of single living cell. From the positions, intensities, and line widths of the Raman peaks in the spectra, we can get useful information about composition, structure and interactions of complexes inside the living cells. External agents may change cell's physiological state and this changed information can also be got from Raman spectra. This article is a study of Raman spectra of human red blood cell (RBC) affected by different intensity direct current (DC); from the result, distinct change of Raman spectra of RBC have been got. These changes characterize the changes of the internal information of the cells. This article give some academic reference of physical therapy using DC in the level of molecule.

In vivo blood glucose quantification using Raman spectroscopy.

We here propose a novel Raman spectroscopy method that permits the noninvasive measurement of blood glucose concentration. To reduce the effects of the strong background signals produced by surrounding tissue and to obtain the fingerprint Raman lines formed by blood analytes, a laser was focused on the blood in vessels in the skin. The Raman spectra were collected transcutaneously. Characteristic peaks of glucose (1125 cm(-1)) and hemoglobin (1549 cm(-1)) were observed. Hemoglobin concentration served as an internal standard, and the ratio of the peaks that appeared at 1125 cm(-1) and 1549 cm(-1) peaks was used to calculate the concentration of blood glucose. We studied three mouse subjects whose blood glucose levels became elevated over a period of 2 hours using a glucose test assay. During the test, 25 Raman spectra were collected transcutaneously and glucose reference values were provided by a blood glucose meter. Results clearly showed the relationship between Raman intensity and concentration. The release curves were approximately linear with a correlation coefficient of 0.91. This noninvasive methodology may be useful for the study of blood glucose in vivo.