Design, fabrication, and performance evaluation of a concave lens array on an aspheric curved surface.

A microlens array (MLA) is a fundamental optical element, which has been widely applied in the fields of imaging sensing, 3D display, and lighting source. However, it is still a challenge to design the MLAs simultaneously satisfying small size, wide field of view, and high image quality. Herein, a novel type of concave lens array on an aspheric convex substrate (CLAACs) is presented, which is composed of an aspheric substrate and a spherical concave subeye array. The facilely designed method of the CLAACs is described and its geometric model is also established by a numerical example. Furthermore, a fabrication method, which is directly machining the CLAACs on PMMA material, is proposed. To realize the ultra-precision machining of the lens, tool path planning is carried out before fabricating. The profile, surface quality, and imaging performance of the fabricated lens are then characterized to reveal its optical capabilities. The results show that the proposed method can realize the rapid design and fabrication of lenses flexibly and efficiently. The fabricated CLAACs exhibit excellent morphology uniformity, high imaging quality, and focusing performance. The study provides a feasible solution for the design and fabrication of such lens arrays with complex discontinuous surfaces.

Perineural invasion detected in prostate biopsy is a predictor of positive surgical margin of radical prostatectomy specimen: A meta-analysis.

The role of perineural invasion detected by puncture biopsy of prostate cancer remains controversial. We performed a meta-analysis to assess the relationship between positive perineural invasion at prostate biopsy and positive surgical margins (PSM) after radical prostatectomy. We searched a number of relevant electronic databases including Web of Science, Medline, PubMed, Embase, and the Cochrane Library until 31 March 2021. STATA 15.1 software was used to analyse all data for this article. The quality of these studies was assessed by the Newcastle-Ottawa Scale (ranged from 0 to 9 stars). Finally, we selected 13 high-quality studies in our meta-analysis, which contain 8283 patients. Overall pooled analysis proposed that biopsy perineural invasion was related to a higher risk of the positive surgical margins after radical prostatectomy in prostate cancer (RR: 1.73; 95% CI: 1.56-1.92; z = 10.30, p = 0.000). Moreover, the outcomes of the publication bias checkout testified that without significant bias arose (Egger's test: 0.086 > 0.05; Begg's test: 0.59 > 0.05). The existing evidence indicates that higher incidence of positive surgical margins in patients who had perineural invasion was detected in prostate biopsy.

Different roles of crayfish hemocytes in the uptake of foreign particles.

Crustacean hemocytes are known to remove invading pathogens by phagocytosis. In this study, we investigated how the semigranular cells (SGCs) and granular cells (GCs) of crayfish Cherax quadricarinatus participated in this process. By injecting the animals with excessive amounts of fluorescent microspheres (FMs), we showed that only a small portion of the circulating hemocytes were phagocytic cells, and they took up FMs in a size-dependent manner. The 0.2 µm FMs were internalized almost entirely by SGCs, while GCs and SGCs both contributed to the uptake of 2 µm FMs. Further analysis of the hemocytes from the animals injected with a mixture of FMs suggested that there were a subpopulation of SGCs specifically ingesting 0.2 µm FMs. The size-dependent manner was also applied to biological particles. Escherichia coli was internalized by both SGCs and GCs, whereas white spot syndrome virus (WSSV) was mostly ingested by SGCs. However, the bacterial cells were rapidly taken and cleared from the circulation by the hemocytes, while the WSSV virions were gradually internalized and remained in the cells for a relatively longer period of time. These findings provide basic information of the phagocytic hemocytes of crayfish and how they respond to different foreign particles.

Replication of thermoplastic polymer spherical lens array using microforged molding technique.

In this paper, we propose a replication method of thermoplastic polymer spherical lens array using a novel microforged mold. The Si3N4 ceramic balls, with 3.5 mm diameter, 10 nm surface roughness and 84 nm deviation from spherical profile, were utilized as indentor to generate aluminum alloy lens array mold. Upon the optimization of technical parameters, such as heating and de-molding temperature, indentation force and holding time, a high quality spherical lens array mold was obtained. The mold was used to fabricate spherical PMMA lens array by hot embossing, which showed excellent characteristics on dimensional stability, surface features and optical performances. Especially for the requirements of deep sag height and low f/#, the microforging technique reveals superior performance for low cost and high quality manufacture of spherical lenses. Compared to the previous complicated tools which requires precise calibration, the self-alignment mode of the balls and cavities can easily guarantee positioning accuracy. Accordingly, the pre-milled spherical cavity deformed uniformly in the process of microforging due to the symmetrical distribution of contact pressure and reduced the error caused by deformation. We believe the proposed microforging technique is an ideal mass production approach to the fabrication of thermoplastic polymer spherical lens array.

Rapid fabrication of thermoplastic polymer refractive microlens array using contactless hot embossing technology.

A thermoplastic polymer refractive microlens array has been rapidly fabricated by contactless hot embossing technology through the stainless steel template with micro through-holes array, which has a diameter of 150 µm and a pitch of 185 µm. By optimizing the technical parameters including heating and demoulding temperature, loading pressure, loading and pressure holding time, a series of high quality microlenses arrays of different sags could be obtained. In addition, the sag and the radius of curvature of the microlens are controllable. The geometrical and optical properties of the microlenses are measured and the influence of temperature and pressure duration on the optical properties of the microlenses are analysed. The results show good surface features and optical performances. Unlike previous contactless hot embossing, a low cost and durable stainless steel template was utilized instead of silicon or nickel mold to avoid valuable equipments and complicated fabrication procedure. Besides, the whole contactless hot embossing process was absence of vacuum equipment. We think that the technology could be an attractive high flexibility method for enhancing efficiency and reducing cost.

Noncontact microembossing technology for fabricating thermoplastic optical polymer microlens array sheets.

Thermoplastic optical polymers have replaced traditional optical glass for many applications, due to their superior optical performance, mechanical characteristics, low cost, and efficient production process. This paper investigates noncontact microembossing technology used for producing microlens arrays made out of PMMA (polymethyl methacrylate), PS (polyStyrene), and PC (polycarbonate) from a quartz mold, with microhole arrays. An array of planoconvex microlenses are formed because of surface tension caused by applying pressure to the edge of a hole at a certain glass transition temperature. We studied the principle of noncontact microembossing techniques using finite element analysis, in addition to the thermal and mechanical properties of the three polymers. Then, the independently developed hot-embossing equipment was used to fabricate microlens arrays on PMMA, PS, and PC sheets. This is a promising technique for fabricating diverse thermoplastic optical polymer microlens array sheets, with a simple technological process and low production costs.

Selective serotonin reuptake inhibitors combined with traditional Chinese medicine for premature ejaculation: A systematic review and meta-analysis.

BACKGROUND: Premature ejaculation (PE) is still a tough problem in drug treatment. Many clinical trials have proven that traditional Chinese medicine (TCM) has a significant effect in the treatment of PE. This article aims to provide the latest evidence for the efficacy and safety of TCM combined with selective serotonin reuptake inhibitors (SSRIs) in the treatment of PE. METHODS: We looked for randomized controlled trials (RCTs) from China National Knowledge Infrastructure, Wanfang, VIP Database, MEDLINE, PubMed, Web of Science, EMBASE, and Cochrane Library until June 30, 2022. STATA 15.1 software was used to analyze all data for this article. The quality of the included articles was evaluated using the Cochrane Reviewer's Handbook 5.3. RESULTS: Finally, we selected 16 high-quality RCTs in our meta-analysis, which containing 889 patients. Meta-analysis suggested that, compared with SSRIs alone, combination of TCM with SSRIs increased significantly intravaginal ejaculation latencv time and the scores of ejaculation control ability, sexual life satisfaction, PE-related distress, and communication difficulties between partners related to PE. Also, there was no significant difference in adverse effects between the two groups. In addition, the results of publication bias test showed that no significant bias occurred. CONCLUSION: The combined use of TCM and SSRIs has significant effect in the treatment of PE compared with SSRIs monotherapy and was generally well tolerated. Due to the small sample size, multicenter and large sample RCT is still needed in the future to further confirm the effectiveness and safety of TCM combined with SSRIs in the treatment of PE.

The Clinical Efficacy of Percutaneous Nephrolithotomy and Flexible Ureteroscopic Lithotripsy in the Treatment of Calyceal Diverticulum Stones: A Meta-Analysis.

BACKGROUND: The clinical efficacy of percutaneous nephrolithotomy (PCNL) and flexible ureteroscopic lithotripsy (FURL) in the treatment of calyceal diverticulum stones (CDs) remains controversial. We performed a meta-analysis to assess the clinical efficacy of PCNL and FURL in the treatment of CDs. METHODS: We searched a number of relevant electronic databases including China National Knowledge Infrastructure (CNKI), MEDLINE, PubMed, Web of Science, EMBASE, and Cochrane Library until January 31, 2022. STATA 15.1 software was used to analyze all data for this article. The quality of these studies was assessed by the Newcastle-Ottawa Scale (ranged from 0 to 9 stars). RESULTS: Finally, we selected 11 high-quality studies in our meta-analysis,which containing 486 patients. Meta-analysis showed that PCNL had higher stone-free rate [OR=3.55, 95% CI: 2.07 -6.10, P = 0.000], symptom-free rate [OR=3.56, 95% CI: 1.51 -8.38, p= 0.004], while it was slightly inferior to the FURL in bleeding volume [SMD = 1.27, 95% CI: (0.67,1.87), P = 0.000], hospital stay [SMD =2.86, 95% CI: 1.75-3.97, P = 0.000] and complication rate [OR =1.92, 95% CI: 1.10-3.33, P = 0.021], and there was no significant difference in operative time [SMD = -0.011, 95% CI: (-0.41,0.39), P = 0.957]. CONCLUSION: PCNL is safe and effective in the treatment of CDs, which can be considered as the first choice for the clinical treatment of CDs.

Solvothermal preparation of spherical Bi2O3 nanoparticles uniformly distributed on Ti3C2T x for enhanced capacitive performance.

Ti3C2T x is a promising new two-dimensional layered material for supercapacitors with good electrical conductivity and chemical stability. However, Ti3C2T x has problems such as collapse of the layered structure and low pseudocapacitance. In this paper, we propose Bi2O3-Ti3C2T x nanocomposites prepared by a solvothermal method, study the impact of Bi2O3 loading on the phase state and microstructure, and evaluate the electrochemical performance of Bi2O3-Ti3C2T x . Studies have shown that spherical Bi2O3 particles were uniformly dispersed in the interlayer and surface of Ti3C2T x , which enlarged the interlayer spacing of the Ti3C2T x and increased the pseudocapacitance. When the mass percentage of Bi2O3 and Ti3C2T x was 30% (TB30), the specific capacity of TB30 was as high as 183 F g-1 at a current density of 0.2 A g-1, which was about 2.8 times that of Ti3C2T x (TB0). Moreover, a typical asymmetric supercapacitor device assembled with TB0 as the positive electrode and TB30 as the negative electrode exhibited a high energy density of 3.92 W h kg-1 and a maximum power density of 36 000 W kg-1 and maintained 77.4% of the initial capacitance after 5000 cycles at a current density of 2 A g-1. Therefore, the Bi2O3-Ti3C2T x as the negative electrode of supercapacitor has broad application prospects in the field of energy storage.

Efficacy of fasudil for the treatment of aneurysmal subarachnoid hemorrhage: A systematic review protocol of randomized controlled trial.

BACKGROUND: This study aims to systematically assess the efficacy and safety of fasudil for the treatment of aneurysmal subarachnoid hemorrhage (ASH). METHODS: This study will include all of randomized controlled trials on the efficacy and safety of fasudil for the treatment of ASH. Ten electronic databases of PubMed, Embase, Cochrane Library, Google Scholar, Web of Science, Ovid, Cumulative Index to Nursing and Allied Health Literature, Allied and Complementary Medicine Database, Chinese Biomedical Literature Database, and China National Knowledge Infrastructure will be searched from inception to the May 1, 2019 without language restrictions. We will also search gray literatures to avoid missing any other potential studies. Two authors will independently perform study selection, data extraction and management, and methodologic quality assessment. The primary outcome is limbs function. The secondary outcomes comprise of muscle strength, muscle tone, quality of life, and adverse events. RESULTS: This study will provide a comprehensive literature search on the current evidence of fasudil for the treatment of ASH from primary and secondary outcomes. CONCLUSION: The results of this study will present evidence to determine whether fasudil is an effective and safety treatment for patients with ASH. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42019136215.

In Situ Image Acquisition and Measurement of Microdroplets Based on Delay Triggering.

An in situ image acquisition apparatus based on delay triggering for visualizing microdroplets formation is described. The imaging system includes a charge-coupled device camera, a motion control card, a driving circuit, a time delay triggering circuit, and a light source. By adjusting the varying trigger delay time which is synchronized with respect to the signal for jetting, the steady sequential images of the droplet flying in free space can be captured real-time by the system. Several image processing steps are taken to measure the diameters and coordinates of the droplets. Also, the jetting speeds can be calculated according to the delay time interval. For glycerin/water (60:40, mass ratio), under the given conditions of the self-made pneumatically diaphragm-driven drop-on-demand inkjet apparatus, the average of diameter and volume are measured as 266.8 µm and 9944 pL, respectively, and the maximum average velocity of the microdroplets is 0.689 m/s. Finally, the imaging system is applied to measure the volume of 200 microsolder balls generated from the inkjet apparatus. The average diameter is 87.96 µm, and the relative standard deviation is 0.83%. The results show good reproducibility. Unlike previous stroboscopic techniques, the present in situ imaging system which is absence of instantaneous high intensity light employs two control signals to stimulate the microdroplet generator and the charge-coupled device (CCD) camera. Hence, the system can avoid the desynchronization problem of signals which control the strobe light-emitting diode (LED) light source and the camera in previous equipment. This technology is a reliable and cost-effective approach for capturing and measuring microdroplets.

Ultrasound-mediated microbubble destruction enhances the therapeutic effect of intracoronary transplantation of bone marrow stem cells on myocardial infarction.

OBJECTIVE: The combination of intracoronary transplantation and ultrasound-mediated microbubble destruction may promote effective and accurate delivery of bone marrow stem cells (BMSCs) into the infarct zone. To test this hypothesis in this study we examined the effectiveness of ultrasound-mediated microbubble destruction in combination with intracoronary transplantation of BMSCs for the treatment of myocardial infarction in canine model of acute myocardial infarction. METHOD: The dogs were randomly assigned to four groups: PBS, ultrasound-mediated microbubble destruction, BMSCs, BMSCs together with ultrasound-mediated microbubble destruction. At 28 days post-surgery, cardiac function and the percentage of perfusion defect area to total left ventricular perfusion area (DA%) were determined by myocardial contrast echocardiography. Nitro blue tetrazolium staining was performed to determine myocardial infarct size, hematoxylin and eosin staining for assessing microvascular injury, Masson's staining for analyzing myocardial tissue collagen, immunohistochemical analysis of α-actin to measure cardiac contractile function and of BrdU-labeled myocardial cells to measure the number of the BMSCs homing to the infarcted region. RESULTS: The transplantation of BMSCs significantly improved heart function and DA% (P < 0.05). The group that received ultrasound-mediated microbubble destruction with BMSCs transplantation showed the most improvement in heart function and DA% (P < 0.05). This group also showed a denser deposition of BMSCs in the coronary artery and more BrdU positive cells in the infarcted region, had the maximum number of α-actin positive cells, showed the smallest myocardial infarct area compared to other groups (P< 0.05). CONCLUSION: Ultrasound-mediated microbubble destruction increases the homing of BMSCs in the target area following intracoronary transplantation, which allows more BMSCs to differentiate into functional cardiomyocytes, thereby reducing myocardial infarct size and improving cardiac function.