CTAB-Modulated Electroplating of Copper Micropillar Arrays for Non-Enzymatic Glucose Sensing with Improved Sensitivity.

Micropillar array electrodes represent a promising avenue for enhancing detection sensitivity and response current. However, existing methods for depositing electrode materials on micropillar arrays often result in uneven distribution, with the thin sidewall layer being less conductive and prone to corrosion. In addressing this issue, this study introduces electroplating to enhance the copper layer on the sidewall of micropillar array electrodes. These electrodes, fabricated through standard microelectronics processes and electroplating, are proposed for non-enzymatic glucose detection, with the copper layer deposited via electroplating significantly enhancing sensitivity. Initially, the impact of cetyltrimethylammonium bromide (CTAB) concentration as an inhibitor on the surface morphology and sensitivity of the plated layer was investigated. It was discovered that CTAB could decrease surface roughness, hinder the development of large and coarse grains, generate small particles, and boost sensitivity. Compared to the uncoated electrode and plating without CTAB, sensitivity was elevated by a factor of 1.66 and 1.62, respectively. Subsequently, the alterations in plating morphology and detection performance within a range of 0.3 ASD to 3 ASD were examined. Sensitivity demonstrated a tendency to increase initially and then decrease. The electrode plated at 0.75 ASD achieved a maximum sensitivity of 3314 µA·mM-1·cm-2 and a detection limit of 15.9 µM. Furthermore, a potential mechanism explaining the impact of different morphology on detection performance due to CTAB and current density was discussed. It was believed that the presented effective strategy to enhance the sensitivity of micropillar array electrodes for glucose detection would promote the related biomedical detection applications.

Controllable self-rotating array beam with an arc-shaped accelerating trajectory.

In this study, a modified interfering vortex phase mask (MIVPM) is proposed to generate a new type of self-rotating beam. The MIVPM is based on a conventional and stretched vortex phase for generating a self-rotating beam that rotates continuously with increasing propagation distances. A combined phase mask can produce multi-rotating array beams with controllable sub-region number. The combination method of this phase was analyzed in detail. This study proves that this self-rotating array beam has an effectively enhanced central lobe and reduced side lobe owing to adding a vortex phase mask compared with a conventional self-rotating beam. Furthermore, the propagation dynamics of this beam can be modulated by varying the topological charge and constant a. With an increase in the topological charge, the area crossed by the peak beam intensity along the propagation axis increases. Meanwhile, the novel self-rotating beam is used for optical manipulation under phase gradient force. The proposed self-rotating array beam has potential applications in optical manipulation and spatial localization.

Self-healing property of the self-rotating beam.

In this study, we demonstrate the self-healing of self-rotating beams with asymmetric intensity profiles. The proposed self-rotating beam exhibits an asymmetric intensity profile and self-healing properties in free-space propagation. In addition, the rotation direction and beam intensity profile of the self-rotating beam can be adjusted using the parameters a and b in the phase function. The effects of the position and size of the obstruction on the self-healing property of a self-rotating beam were studied both experimentally and numerically. The simulation and experimental results demonstrate that a self-rotating beam can overcome a block of obstacles and regenerate itself after a characteristic distance. Transverse energy flows were used to explain the self-healing properties. Moreover, the beam rotates during propagation, which can be used to capture and manipulate microscopic particles in a three-dimensional space. It is expected that these rotating beams with self-healing properties will be useful in penetrating obstacles for optical trapping, transportation, and optical therapy.

Self-rotating beam in the free space propagation.

We introduce a class of self-rotating beams whose intensity profile tends to self-rotate and self-bend in the free space propagation. The feature of the self-rotating beams is acceleration in the three-dimensional (3D) space. The acceleration dynamics of the self-rotating beams is controllable. Furthermore, multiple self-rotating beams can be generated by a combined diffractive optical element (DOE) simultaneously. Such a beam can be viewed as evolution of a vortex beam by changing the exponential constant of phase. We have generated this beam successfully in the experiment and observed the expected phenomenon, which is basically consistent with the result of the numerical simulation. Our results may provide new insight into the self-rotating beam and extend potential applications in optical imaging.

Impact of Hydrogen Voiding in Chip-to-Chip Electroless All-Copper Interconnections.

Three-dimensional (3D) integration has become a leading approach in chip packaging. The interconnection density and reliability of micro-bumps in chip stacking are often threatened by high bonding temperatures. The method of building chip-to-chip interconnections by electroless deposition of metal has its distinct merit, while the interfacial defect issue, especially that related to voiding during the merging of opposite sides, remains largely unsolved. In this study, to trace the influencing factors in the voiding, the growth characteristics of the electroless all-copper interconnections were examined by carrying out deposition experiments in a microfluidic channel device. The results show that when the gap between the opposite copper bumps to be electrolessly merged is as low as 10 µm, significant voids appear at the inflow side and the top of the copper bumps because the hydrogen cannot be expelled in time. A finite-element flow model of the plating solution between the chips was established, which showed that the flow rate of the plating solution around the copper bumps was much higher than in the merging gap, causing an uneven supply of reactants. Based on these findings, we proposed two potential solutions, one is to improve the flow mode of the plating solution, and the other is to add the reaction inhibitor, 2,2'-bipyridine. Finally, the combination of these two approaches successfully achieved an improved merging quality of the copper joints.

A Case-Control Study on Factors of HPV Vaccination for Mother and Daughter in China.

(1) Background: To explore the influencing factors of human papillomavirus (HPV) vaccination among mothers and daughters so as to provide evidence and strategies for improving the HPV vaccination rate of 9-18-years-old girls. (2) A questionnaire survey was conducted among the mothers of 9-18-year-old girls from June to August 2022. The participants were divided into the mother and daughter vaccinated group (M1D1), the mother-only vaccinated group (M1D0), and the unvaccinated group (M0D0). Univariate tests, the logistic regression model, and the Health Belief Model (HBM) were employed to explore the influencing factors. (3) Results: A total of 3004 valid questionnaires were collected. According to the regions, Totally 102, 204, and 408 mothers and daughters were selected from the M1D1, M1D0, and M0D0 groups, respectively. The mother having given her daughter sex education (OR = 3.64; 95%CI 1.70, 7.80), the mother's high perception of disease severity (OR = 1.79; 95%CI 1.02, 3.17), and the mother's high level of trust in formal information (OR = 2.18; 95%CI 1.26, 3.78) were all protective factors for both the mother and her daughter's vaccination. The mother's rural residence (OR = 0.51; 95%CI 0.28, 0.92) was a risk factor for vaccination of both mother and daughter. The mother's education of high school or above (OR = 2.12; 95%CI 1.06, 4.22), the mother's high level of HPV and HPV vaccine knowledge (OR = 1.72; 95%CI 1.14, 2.58), and the mother's high level of trust in formal information (OR = 1.72; 95%CI 1.15, 2.57) were protective factors of mother-only vaccination. The older the mother (OR = 0.95; 95%CI 0.91, 0.99) was classed as a risk factor for mother-only vaccination. "Waiting until the daughters are older to receive the 9-valent vaccine" is the main reason why the daughters of M1D0 and M0D0 are not vaccinated". (4) Chinese mothers had a high willingness to vaccinate their daughters with the HPV vaccine. The higher education level of the mother, giving sex education to the daughter, the older ages of mothers and daughters, the mother's high level of HPV and HPV vaccine knowledge, a high level of perception of the disease severity, and a high level of trust in formal information were promoting factors of HPV vaccination for mother and daughter, and rural residence was a risk factor to vaccination. To promote HPV vaccination in girls from 9-18 years old, communities could provide health education to rural mothers with low education levels; the government could advocate for HPV vaccination through issuing policy documents; and doctors and the CDC could popularize the optimal age for HPV vaccination to encourage mothers to vaccinate their daughters at the age of 9-14 years old.

Experiment and simulation of single inhibitor SH110 for void-free TSV copper filling.

Three-dimensional integration with through-silicon vias (TSVs) is a promising microelectronic interconnection technology. Three-component additives are commonly used for void-free TSV filling. However, optimising the additive concentrations is an expensive process. To avoid this, a single-component additive was developed: 3-(2-(4,5-dihydrothiazol-2-yl) disulfanyl) propane-1-sulfonic acid/sulfonate (SH110). Sodium 3,3'-dithiodipropane sulfonate (SPS) and SH110 were used as additives for TSV electroplating copper filling. SH110 resulted in void-free filling, whereas large keyhole voids were found for SPS. To understand how the additives affect the filling mechanism, linear sweep voltammetry of the plating solutions was carried out. The interactions between the Cu surface and additives were simulated by molecular dynamics (MD) analysis using Materials Studio software, and quantum chemistry calculations were conducted using GAUSSIAN 09W. SH110 adsorbs to the Cu surface by both 4,5-dihydrothiazole (DHT) and 3-mercaptopropane sulfonate (MPS) moieties, while SPS is adsorbed only by MPS moieties. MD simulations indicated that the adsorption of the coplanar MPS moiety is the main factor governing acceleration. Quantum chemistry calculations showed that DHT provides an inhibitory effect for TSV filling, while MPS acts as an accelerator for SH110. SH110 is an excellent additive exhibiting both the acceleration and the suppression necessary for achieving void-free TSV filling.

Graphene/Glycerin Solution-Based Multifunctional Stretchable Strain Sensor with Ultra-High Stretchability, Stability, and Sensitivity.

Highly stretchable, flexible, and sensitive strain sensors have promising applications in motion detection-especially multifunctional strain sensors that can detect stretching, bending, compression and twisting. Herein, this study presents a graphene and glycerol solution-based multifunctional sensor with ultra-high stretchability and sensitivity. Owing to the self-lubrication and fluidity of the graphene-glycerol solution, the strain sensors display super stretchability up to 1000%, a maximum gauge factor up to 45.13, and excellent durability for over 10,000 cycles. In addition, the sensor can also rapidly respond to small strains (1%, 5%, 10%) and different stretching rates (12.5%/s, 25%/s, 50%/s, and 100%/s). More impressively, the sensors can measure up to 50 kPa pressure and 180° twisting without any damage. Furthermore, the strain sensors demonstrate their applicability in scenarios involving motion detection, such as that for finger bending, wrist rotating, touching, and drinking water.

Involvement of multidrug resistance protein 4 in the hepatocyte efflux of lamivudine and entecavir.

Multidrug resistance protein 4 (MRP4) is capable of transporting acyclic nucleotide phosphonates, but little is known about its role in lamivudine (LAM) and entecavir (ETV) transport. In the present study, the involvement of MRP4 in the transport of LAM and ETV was investigated through in vitro experiments. The cytotoxicity of three antiviral drugs and their activities against HBV as characterized in HepG2.4D14 [wild­type hepatitis B virus (HBV)] and HepG2.A64 (ETV­resistant HBV) cells. LAM, ETV and tenofovir (TFV) demonstrated a 50% effective concentration against HBV of 4.14±0.03, 0.13±0.02 and 3.24±0.01 µM in HepG2.4D14 cells and of 5.94±0.20, 6.28±0.07 and 11.43±0.09 µM in HepG2.A64 cells, respectively. After administering 3-([(3-(2-[7-chloro-2-quinolinyl]ethyl)phenyl]-[(3-dimethylamino-3-oxoporphyl)-thio)-methyl]-thio) propanoic acid (MK571), the intracellular concentrations of all three drugs were much lower than the extracellular drug concentrations in these two cell types, whereas the intracellular drug concentrations in wild­type cells were higher than those in ETV­resistant cells. Furthermore, the intracellular levels of LAM, ETV and TFV were enhanced and the extracellular concentrations were reduced by addition of MK571. Thus, MRP4 is mainly responsible for the efflux of LAM and ETV in hepatocyte cultures. These results may contribute to enhancing antiviral efficacy.

Dynamic through-silicon-via filling process using copper electrochemical deposition at different current densities.

This work demonstrates the dynamic through-silicon-via (TSV) filling process through staged electrodeposition experiments at different current densities. Different morphologies corresponding to TSV filling results can be obtained by controlling the applied current density. Specifically, a low current density (4 mA/cm2) induces seam defect filling, a medium current density (7 mA/cm2) induces defect-free filling, and a high current density (10 mA/cm2) induces void defect filling. Analysis of the filling coefficient indicates that the effect of current density on the TSV filling models is triggered by the coupling effect of consumption and diffusion of additives and copper ions. Further, the morphological evolution of plating reveals that the local deposition rate is affected by the geometrical characteristics of the plating.

Simple and rapid mercury ion selective electrode based on 1-undecanethiol assembled Au substrate and its recognition mechanism.

A simple and rapid mercury ion selective electrode based on 1-undecanethiol (1-UDT) assembled Au substrate (Au/1-UDT) has been well constructed. 1-UDT was for the purpose of generating self-assembled monolayer on gold surface to recognize Hg2+ in aqueous solution, which had a working concentration range of 1.0×10-8-1.0×10-4molL-1, with a Nernst response slope of 28.83±0.4mV/-pC, a detection limit of 4.5×10-9molL-1, and a good selectivity over the other tested cations. Also, the Au/1-UDT possessed good reproducibility, stability, and short response time. The recovery obtained for the determination of mercury ion in practical tremella samples was in the range of 99.8-103.4%. Combined electrochemical analysis and X-ray photoelectron spectroscopy (XPS) with quantum chemical computation, the probable recognition mechanism of the electrode for selective recognition of Hg2+ has been investigated. The covalent bond formed between mercury and sulfur is stronger than the one between gold and sulfur and thus prevents the adsorption of 1-UDT molecules on the gold surface. The quantum chemical computation with density functional theory further demonstrates that the strong interaction between the mercury atom and the sulfur atom on the gold surface leads to the gold sulfur bond ruptured and the gold mercury metallophilic interaction.

Dispensing of high concentration Ag nano-particles ink for ultra-low resistivity paper-based writing electronics.

Paper-based writing electronics has received a lot of interest recently due to its potential applications in flexible electronics. To obtain ultra-low resistivity paper-based writing electronics, we developed a kind of ink with high concentration of Ag Nano-particles (up to 80 wt%), as well as a related dispensing writing system consisting an air compressor machine and a dispenser. Additionally, we also demonstrated the writability and practical application of our proposed ink and writing system. Based on the study on the effect of sintering time and pressure, we found the optimal sintering time and pressure to obtain high quality Ag NPs wires. The electrical conductivity of nano-silver paper-based electronics has been tested using the calculated resistivity. After hot-pressure sintering at 120 °C, 25 MPa pressure for 20 minutes, the resistivity of silver NPs conductive tracks was 3.92 × 10(-8) (Ωm), only 2.45 times of bulk silver. The mechanical flexibility of nano-silver paper-based electronics also has been tested. After 1000 bending cycles, the resistivity slightly increased from the initial 4.01 × 10(-8) to 5.08 × 10(-8) (Ωm). With this proposed ink preparation and writing system, a kind of paper-based writing electronics with ultra-low resistivity and good mechanical flexibility was achieved.

Effects of applied potential and the initial gap between electrodes on localized electrochemical deposition of micrometer copper columns.

Micrometer copper columns were fabricated via a technology named localized electrochemical deposition (LECD). This paper studies the effects of applied potential and the initial gap between electrodes on the LECD process. The surface and cross sectional morphologies, as well as the average deposition rate were investigated to evaluate the quality of the deposited copper columns. Results demonstrated that the copper columns tended to be cylinder-shape with few voids inside at lower potential (<2.4 V). Whereas,the copper columns tended to be dendriform-shape with lots of voids inside at larger potential (>2.8 V). The average deposition rate increased with the raise of potential. In addition, the copper columns tended to be cylinder-shape with the initial gap between electrodes to be 10 µm or below. However, the copper columns tended to be cone-shape when the initial gap between electrodes became larger (35 µm or above). The number of voids inside the copper column and the average deposition rate both decreased with the increase of the initial gap. Moreover, the process of LECD under varied electric field has also been simulated using COMSOL software, and the formation of cylindrical and conical copper columns was further explained based on the electric field distribution at the cathode.

Ultrasound aided smooth dispensing for high viscoelastic epoxy in microelectronic packaging.

Epoxy dispensing is one of the most critical processes in microelectronic packaging. However, due its high viscoelasticity, dispensing of epoxy is extremely difficult, and a lower viscoelasticity epoxy is desired to improve the process. In this paper, a novel method is proposed to achieve a lowered viscoelastic epoxy by using ultrasound. The viscoelasticity and molecular structures of the epoxies were compared and analyzed before and after experimentation. Different factors of the ultrasonic process, including power, processing time and ultrasonic energy, were studied in this study. It is found that elasticity is more sensitive to ultrasonic processing while viscosity is little affected. Further, large power and long processing time can minimize the viscoelasticity to ideal values. Due to the reduced loss modulus and storage modulus after ultrasonic processing, smooth dispensing is demonstrated for the processed epoxy. The subsequently color temperature experiments show that ultrasonic processing will not affect LED's lighting. It is clear that the ultrasonic processing will have good potential to aide smooth dispensing for high viscoelastic epoxy in electronic industry.

Dipping Process Characteristics Based on Image Processing of Pictures Captured by High-speed Cameras.

The dipping process was recorded firstly by high-speed camera system; acceleration time, speed, and dipping time were set by the control system of dipping bed, respectively. By image processing of dipping process based on Otsu's method, it was found that low-viscosity flux glue eliminates the micelle effectively, very low speed also leads to small micelle hidden between the bumps, and this small micelle and hidden phenomenon disappeared when the speed is ≥0.2 cm s-1. Dipping flux quantity of the bump decreases by about 100 square pixels when flux viscosity is reduced from 4,500 to 3,500 mpa s. For the 3,500 mpa s viscosity glue, dipping flux quantity increases with the increase of the speed and decreases with the increase of the speed after the speed is up to 0.8 cm s-1. The stable time of dipping glue can be obtained by real-time curve of dipping flux quantity and is only 80-90 ms when dipping speed is from 1.6 to 4.0 cm s-1. Dipping flux quantity has an increasing trend for acceleration time and has a decreasing trend for acceleration. Dipping flux quantity increases with the increase of dipping time, and is becoming saturated when the time is ≥55 ms.

An outbreak of adult measles by nosocomial transmission in a high vaccination coverage community.

OBJECTIVES: The aims of this study were to determine the mechanism of an outbreak of measles in adults and to provide scientific measures for putting forward a measles elimination program. METHODS: We performed a cross-sectional investigation during the measles outbreak to identify a possible communication link. RESULTS: From November 1, 2011 to January 26, 2012, the town reported 11 cases of measles in total. The case study identified an obvious propagation chain, which showed ordered and intimate exposure between cases. CONCLUSIONS: Hospital exposure 1-2 weeks before infection with measles was the main cause of the measles outbreak. We must be fully aware of the possibility of nosocomial infection in an outbreak of measles; controlling nosocomial infections is a vital step in the prevention and control of the propagation of measles.

Cytotoxicity of 5-Aza-2'-deoxycytidine against gastric cancer involves DNA damage in an ATM-P53 dependent signaling pathway and demethylation of P16(INK4A).

The DNA methylation inhibitor 5-Aza-2'-deoxycytidine (5-Aza-CdR) has increasingly attracted worldwide attention for its antineoplastic potential. The cytotoxitic mechanisms, however, especially, the relative contribution of silenced genes reactivation by demethylation and enzyme-DNA adduct formation to the efficacy of 5-Aza-CdR is still a crucial unresolved question. In this investigation, we demonstrated that 5-Aza-CdR treatment resulted in growth suppression in a concentration and time-dependent manner and G2 phrase arrest - hallmarks of a DNA damage response in gastric cancer AGS cells. Formation of DNA double-strand breaks, as monitored by comet assay was examined in an ATM (ataxia-telangiectasia mutated)-dependent manner based on the fact that PI3K inhibitor Wortmannin abolished the action of cytotoxicity of 5-Aza-CdR. Upon treatment with 5-Aza-CdR, ATM activation was clearly associated with P53 phosphorylation at Ser(15), which was directly responsible for 5-Aza-CdR modified P21(Waf1/Cip1) expression. Further exploration revealed that demethylation of P16(INK4A) correlated with the strikingly down-regulated expressions of DNA methyltransferase 3A as well as 3B was, at least in part, attributed to the cytotoxicity of 5-Aza-CdR in AGS cells. Conclusively, these results greatly enhance our understanding of the mechanisms of cytotoxicity of 5-Aza-CdR and strongly provide the preclinical rationale for an assessment of 5-Aza-CdR to ameliorate patient outcome with gastric cancer.

5-Aza-2'-deoxycytidine induces cytotoxicity in BGC-823 cells via DNA methyltransferase 1 and 3a independent of p53 status.

The DNA methylation inhibitor 5-aza-2'-deoxycytidine (5-Aza-CdR) has therapeutic value for the treatment of cancer. However, the mechanism by which 5-Aza-CdR induces antineoplastic activity is not clear. The efficacy of 5-Aza-CdR on the contribution of gene reactivation by demethylation and enzyme-DNA adduct formation is an important unresolved question. The aim of this study was to explore the mechanism of the effect of 5-Aza-CdR on human gastric cancer growth. Human BGC-823 cells were treated with different concentrations of 5-Aza-CdR for different durations. Cell viability, DNA damage and gene expression were determined. The results showed that 5-Aza-CdR at low concentrations induced inhibition of gastric cancer BGC-823 cell proliferation as well as increased apoptosis caused by DNA damage. For the first time, we demonstrated that 5-Aza-CdR-induced cytotoxicity against BGC-823 cells was predominantly regulated via upregulation of DNA methyltransferase 1, 3a and partially via reactivation of RUNX3, which was independent of p53 status and its ability to activate p21Waf1/Cip1 expression. To our knowledge, this is the first demonstration of p53-independent 5-Aza-CdR action on DNA methyltransferases and demethylation. These results strongly provide the preclinical rationale for the clinical evaluation of 5-Aza-CdR to improve patient outcome in gastric cancer.