Metagenomic Next-Generation Sequencing as an Effective Diagnostic Tool for Talaromycosis in HIV-Negative Patients.

The diagnosis of Talaromyces marneffei infection in HIV-negative patients remains challenging. There is an urgent need for rapid and convenient methods to diagnose this complicated disease. The aim of this study was to evaluate the diagnostic efficiency of metagenomic next-generation sequencing (mNGS) for talaromycosis in non-HIV-infected patients by comparing mNGS with traditional microbial culture. In total, 66 samples from 57 patients were analyzed via both mNGS and microbial culture. The ROC curve showed a sensitivity for mNGS of 97.22%, which was greater than that of microbial culture (61.11%). Samples from the respiratory tract, infectious skin lesions, and lymph nodes are recommended as routine samples for talaromycosis detection via mNGS. Furthermore, mNGS significantly reduced the diagnostic time compared to microbial culture. Overall, our study demonstrated that mNGS is a promising tool for rapid and accurate pathogenic detection in HIV-negative patients with talaromycosis.

The Epidemiology of Tinea Capitis in Guangxi Province, China.

The aim of this study was to analyze the epidemiological characteristics and pathogen spectrum of tinea capitis in Guangxi, southern China. A multicenter prospective descriptive study was conducted in 8 hospitals across Guangxi. From January 2019 to July 2022, one hundred seventy-one (171) patients diagnosed with tinea capitis were included. Demographic data, risk factors, and fungal data were collected. If necessary, species were further identified by morphological or molecular sequencing in the central laboratory. Of the 171 cases of tinea capitis, 74.3% occurred in patients aged 2-8 years. Children with tinea capitis were mainly boys (59.6%) and were more likely than adults to have a history of animal contact (44.2% vs. 33.3%) and zoophilic dermatophyte infection (76.9% vs. 46.7%, P = 0.008). The adults were mainly female (53%) and were more likely than children to have a history of infection with anthropophilic organisms (53.3% vs. 18.9%). The causative agents of tinea capitis in Guangxi were diverse, and the most common pathogen was Microsporum canis (M. cani, n = 98, 62%), followed by Trichophyton mentagrophytes (T. mentagrophytes n = 18, 11.4%) and Trichophyton tonsurans (T. tonsurans n = 12, 7.6%). In addition, tinea capitis caused by Nannizzia incurvata (N. incurvata) and Trichophyton verrucosum (T. verrucosum) was detected in the study. Notably, the proportion of patients with kerion in the study was 41.5% (n = 71), and most of those patients were children (n = 68), especially neglected children living in the rural mountainous areas of Guangxi, where they were unable to receive timely diagnosis and appropriate treatment. In conclusion, the causative agents of tinea capitis in Guangxi, South China, are diverse, and the incidence of kerion is high, indicating that diagnosis and treatment modalities in the region remain grossly inadequate. Clinicians and policy-makers should collaborate to adopt public health strategies to control the disease.

Clinical characteristics of infants with port-wine stain and glaucoma secondary to Sturge-Weber Syndrome.

BACKGROUND: Sturge-Weber Syndrome (SWS) is a rare disease involving the eye, skin, and brain. Port-wine stain (PWS) and glaucoma are common clinical manifestations. This study analysed the clinical characteristics of infants with PWS and glaucoma secondary to SWS. METHODS: Children with PWS and glaucoma secondary to SWS were enrolled. Data were extracted from ophthalmic and systemic examination findings. Ocular examinations included intraocular pressure, anterior segment and fundus examination, and ocular A-scan and B-scan ultrasonography. RESULTS: Fifty-seven patients were included, with a mean age of 9.9 ± 11.9 months, and 34 (59.6%) patients were male. In all, 61 eyes were diagnosed with glaucoma. Forty-one patients (71.9%) had unilateral facial PWS and glaucoma occurred on the same side. Eight patients (14.0%) had Mongolian spots and ten patients (17.5%) had epilepsy. Corneal changes included corneal oedema (n = 36 eyes, 59.0%), corneal opacity (n = 15 eyes, 24.6%), and Haab lines (n = 13 eyes, 21.3%). Mean corneal diameter and thickness in the eyes with glaucoma was larger than those in the unaffected eyes (12.2 ± 0.7 mm vs 10.8 ± 0.6 mm, P < 0.001; 681.2 ± 106.4 µm vs 578.2 ± 58.2 µm, P < 0.001). The eyes with glaucoma had higher IOP and larger axial length and C/D ratio (19.3 ± 6.2 mmHg vs 11.6 ± 4.2 mmHg, P < 0.001; 21.23 ± 1.93 mm vs 19.68 ± 1.61 mm, P < 0.001; and 0.57 ± 0.18 vs 0.24 ± 0.15, P < 0.001). Thirty-three (57.9%) and 25 (43.9%) patients showed diffuse choroidal haemangioma (DCH) and conjunctival/episcleral haemangiomas, respectively. Ten patients (17.5%) showed iris anterior insertion or hyperpigmentation in the anterior chamber angles. Six of them had Mongolian spots at the same time. CONCLUSIONS: Monocular glaucoma, DCH, and conjunctival/episcleral haemangiomas are common in SWS patients with PWS and glaucoma. Glaucomatous eyes have larger corneal diameter and axial length and thicker cornea. Patients with Mongolian spots have higher incidence of iris anterior insertion or hyperpigmentation in anterior chamber angle.

The occurrence timeline of steroid-induced ocular hypertension and cataract in children with systemic autoimmune diseases.

PURPOSE: Steroid-induced ocular hypertension (SIOH) and cataract can result in visual loss. This study evaluated the timetable of SIOH and steroid-induced posterior subcapsular cataract (SI-PSC) occurrences in children with systemic autoimmune diseases (SAD) undergoing long-term systemic corticosteroid treatment. METHODS: Thirty-seven children with SAD treated with long-term oral corticosteroids were enrolled in this study. Intraocular pressure (IOP), SI-PSC occurrences, visual field and peripapillary retinal nerve fibre layer (pRNFL) thicknesses were recorded every 3 months for at least 6 months. RESULTS: Of the 37 children, with average age 11.0 ± 2.9 years, 22 patients (59.5%) had SIOH, 2 progressed as glaucoma at the 18-month and 3-year follow-up, respectively, and 12 (32.4%) patients had SI-PSC. Among patients with SIOH, 45.5% (10/22) of them had SI-PSC occurrence, and among patients with normal IOP, 13.3% (2/15) of them had SI-PSC. Seventeen patients participated in a longitudinal study with a follow-up period of at least 18 months. The incidence of SIOH started at 1 month 52.9% (9/17) and gradually increased to 70.6% (12/17) at 6 months, then decreased to 35.3% (6/17). SI-PSC onset started at 6 months (17.6%, 3/17), and its occurrence increased to 35.3% (6/17) at 12 months and reached to 41.2% (7/17) at 18 months. The pRNFL was thicker in the children with SIOH than the healthy controls (p = 0.01). CONCLUSION: SIOH and SI-PSC are common coexistent complications in children with long-term corticosteroids treatment, and the occurrence time is during the first month and 6 months, respectively. Patients with SIOH have a higher probability of cataract.

PGM5 is a promising biomarker and may predict the prognosis of colorectal cancer patients.

BACKGROUND: Phosphoglucomutase (PGM), a key enzyme in the metabolism of glucose-1-phosphate and glucose-6-phosphate, has been found to be associated with proliferation, invasion, and metastasis of cancer. However, the expression and function of PGM5 in colorectal cancer (CRC) remains unknown. METHODS: We tested PGM5 mRNA and protein expression levels in 79 CRC tissue and their matched adjacent tissue samples by qRT-PCR and immunohistochemistry, respectively. Overall survival (OS) was estimated with the Kaplan-Meier method and compared between groups with the log-rank test. We performed multivariable Cox regression analyses to identify factors associated with CRC risk. The cell proliferation, migration and invasion abilities of CRC cells were detected by using CCK-8, Transwell migration and invasion assays, respectively. RESULTS: The PGM5 protein levels expression in CRC tissues were significantly lower than those in the adjacent tissues (t = 5.035, P < 0.001), and Kaplan-Meier analysis indicated that low PGM5 expression were significantly associated with poor overall survival (P = 0.0069). Univariate and multivariate analyses demonstrated that PGM5 was an independent risk factor for overall survival (hazard ratio = 0.3951, P = 0.014). PGM5 overexpression significantly inhibited the proliferation, invasion and migration abilities of CRC cells. On the contrary, knockdown of PGM5 promotes the invasion and migration of CRC cells. CONCLUSIONS: PMG5 regulates proliferation, invasion, and migration in the CRC and decreased PGM5 is associated with poor prognosis. Therefore, PGM5 is a promising biomarker in CRC and decreased PGM5 may predict poor overall survival in patients with CRC.

Palliative treatment of malignant colorectal obstruction caused by advanced malignancy: a self-expanding metallic stent or surgery? A system review and meta-analysis.

We conducted a meta-analysis to compare the outcomes of a self-expanding metallic stent (SEMS) vs. surgery for the palliative treatment of colorectal obstruction caused by advanced colorectal malignancy. The databases of MEDLINE, EMBASE, Cochrane controlled trials registry and the Chinese Wanfang were retrieved (updated to 31 August 2011) to identify eligible studies. We calculated the odds ratio or weighted mean difference and its corresponding 95 % confidence interval. In total, nine primary studies were included in this analysis. The success rate of SEMS placement was 93.9 %, with short-term and long-term complication rates of 26.2 and 16.1 %, respectively. Combined analyses revealed that the SEMS group had a similar risk of short-term complications as the surgical group (P = 0.22). Moreover, SEMS was not associated with a higher mortality risk than surgical intervention (P = 0.22) and it required a significantly shorter hospitalization time (P < 0.01); however, SEMS patients had a higher risk of long-term complications (P = 0.03). Because of great heterogeneities between patients and chemoradiotherapy, we did not analyze the survival times of the two groups. These results support the feasibility of SEMS as a palliative treatment for malignant colorectal obstruction caused by incurable malignancy, as it requires shorter hospitalization and is followed by quick recovery. However, the risk of long-term complications such as perforation and stent migration should be borne in mind.

Re-evaluation for systematic reviews of traditional Chinese medicine in the treatment of chronic bronchitis.

BACKGROUND: Chronic bronchitis (CB) is a common clinical chronic respiratory disease, which has a high incidence in the middle aged and elderly population. With the development of the disease, the number of acute attacks becomes more and more frequent, which leads to the continuous decrease of lung function. If not treated in time, it will lead to a variety of complications and seriously affect the quality of life of patients. Traditional Chinese medicine (TCM) or TCM combined with western medicine is highly effective in the treatment of CB disease. In recent years, there are many systematic reviews on the use of TCM therapy in the treatment of CB, and the efficacy and safety of TCM in the treatment of CB diseases are evaluated. The aim of this study was to re-evaluate the Meta analysis/Systematic reviews (MAs/SRs) of TCM for the treatment of CB, aiming to provide a clinical basis for the treatment of CB by TCM. METHODS: Retrieval among Chinese and English databases such as China National Knowledge Infrastructure, Wanfang database, China Scientific Journals Database, SinoMed, PubMed, Web of Science, The Cochrane Library and EMbase, etc. were conducted within the duration from database establish Tion date to March 2023.The included research was independently conducted by 2 researchers for literature screening, data extraction, and quality evaluation. The AMSTAR 2 scale was used to evaluate the quality of the report, the PRISMA 2020 statement evaluated the quality of the report, the ROBIS tool evaluated the risk of bias, and the GRADE quality evaluation tool evaluated the quality of the evidence. RESULTS: Fifteen MAs/SRs were included, for a total of 224 studies involving 20,710 patients with CB. The 15 studies included in AMSTAR 2 are of very low quality. The ROBIS evaluation results showed that 8 MAs/SRs were considered to have high risk and 7 with low risk. The PRISMA 2020 report quality showed evaluation results of the included studies scores between 24 and 30, among them 13 with high quality and 2 with low quality. The GRADE system results showed that, within 70 outcome indicators, only 14 of them have moderate quality for evidence, with 31 for low quality, 25 for very low quality, and none for high quality. CONCLUSION: The MAs/SRs methodological quality of using TCM for treatment CB is generally poor, the quality of reports as well as evidence are generally low, and the risk of bias is high, therefore we should treat these results with caution.

Outcomes of Microcatheter-Assisted Trabeculotomy for Glaucoma Associated With Sturge-Weber Syndrome and Phakomatosis Pigmentovascularis.

PURPOSE: To evaluate mid-term efficacy and safety of ab externo Microcatheter-assisted trabeculotomy (MAT) for early-onset glaucoma associated with Sturge-Weber syndrome (SWS) and phakomatosis pigmentovascularis (PPV). DESIGN: Retrospective, non-comparative, interventional case series. METHODS: Medical records of consecutive SWS- or PPV-associated glaucoma patients who had undergone ab externo MAT between August 2017 and April 2020 at Beijing Children's Hospital were reviewed. Success was defined as an intraocular pressure (IOP) of <21 mmHg with (qualified success) or without (complete success) the use of antiglaucoma medication. RESULTS: Overall, 13 eyes (12 patients) with SWS and 9 eyes (8 patients) with PPV were included, with a mean age of 12.8 ± 15.8 months at the time of surgery and a mean follow-up time of 39.5 ±10.4 months. Both the SWS (26.5 ± 5.3 mmHg at baseline vs 16.5 ± 5.0 mmHg at the last visit; P < .001) and PPV (29.2 ± 7.5 mmHg vs 23.4 ± 4.7 mmHg; P = .014) subsets achieved a statistically significant fall in IOP following surgery. The Kaplan-Meier survival rate of complete (qualified) success after 42 months was 76.2% (87.5%) and 22.2% (40.0%) for eyes with SWS and PPV, respectively. Complications were minimal. Phakomatosis pigmentovascularis was associated with worse surgical outcomes. CONCLUSIONS: Ab externo MAT is an effective and safe treatment for early-onset glaucoma associated with SWS, but a gradual increase in IOP over time was noted in some patients. Ab externo MAT has limited efficacy for early-onset glaucoma associated with PPV in the mid-term.

Self-assembly, alignment, and patterning of metal nanowires.

Armed with the merits of one-dimensional nanostructures (flexibility, high aspect ratio, and anisotropy) and metals (high conductivity, plasmonic properties, and catalytic activity), metal nanowires (MNWs) have stood out as a new class of nanomaterials in the last two decades. They are envisaged to expedite significantly and even revolutionize a broad spectrum of applications related to display, sensing, energy, plasmonics, photonics, and catalysis. Compared with disordered MNWs, well-organized MNWs would not only enhance the intrinsic physical and chemical properties, but also create new functions and sophisticated architectures of optoelectronic devices. This paper presents a comprehensive review of assembly strategies of MNWs, including self-assembly for specific structures, alignment for anisotropic constructions, and patterning for precise configurations. The technical processes, underlying mechanisms, performance indicators, and representative applications of these strategies are described and discussed to inspire further innovation in assembly techniques and guide the fabrication of optoelectrical devices. Finally, a perspective on the critical challenges and future opportunities of MNW assembly is provided.

Case Report: First Case of Endophthalmitis Caused by an Emerging Pathogen: Nocardia huaxiensis.

Nocardia endophthalmitis is a relatively uncommon form of endophthalmitis seen in clinical patients. In general, Nocardia endophthalmitis tends to carry a poor prognosis. Here, we report a 3-year-old child who was admitted to the hospital due to a rupture of the left eye. The suturing and anterior chamber formation were performed immediately. Approximately, 16 days after the operation, massive whitish plump and tufted exudates gathered in the pupil area and at the bottom of the anterior chamber, and the child was diagnosed with endophthalmitis. The infection was initially considered to be caused by fungal pathogens for that the hyphae and spores were observed in the smear. However, the isolate obtained after 4 days of culturation was identified as actinomycetes using MALDI-TOF. We further classified it as Nocardia huaxiensis by next-generation sequencing (NGS) based on the MinION platform. Amikacin and sulfamethoxazole tablets were used to control the infection and the ocular inflammation subsided gradually. Intraocular lens (IOL) implantation is planned to be performed at an appropriate future time to improve his vision. Nocardia endophthalmitis is rare and usually caused by ocular trauma or surgery. In conclusion, Nocardia huaxiensis should be considered as an emerging pathogen and deserves more attention.

The Relationship between the Aqueous VEGF Level and the Severity of Type 1 Retinopathy of Prematurity.

PURPOSE: To analyze the relationship between the severity of type 1 retinopathy of prematurity (ROP) and the level of vascular endothelial growth factor (VEGF) in aqueous fluid. METHODS: The aqueous VEGF levels of 49 patients (88 eyes) with type 1 ROP were retrospectively analyzed. These eyes were categorized into three groups according to the severity of disease: aggressive retinopathy of prematurity (A-ROP), threshold of ROP (T-ROP), and type 1 pre-threshold ROP (P-T-1). The differences in aqueous VEGF levels among these three groups were compared. The relationship between the aqueous VEGF level and the retinal changes of ROP, including the vessel tortuosity in zone I, and the location and stage of the ROP lesions, were also analyzed. RESULTS: The aqueous VEGF level of the A-ROP group was the highest among the three groups, followed by those of the T-ROP and P-T-1 groups. The aqueous VEGF level was negatively correlated with the zone and the stage of the ROP diseases, while it was positively correlated with the venous tortuosity in zone I and had no relevance with the artery tortuosity in zone I. CONCLUSIONS: The aqueous VEGF level in A-ROP was the highest in type I ROP. The location of the ROP lesions and the venous tortuosity in zone I correlated with the aqueous VEGF level and could indicate the severity of ROP.

Population pharmacokinetics of voriconazole and initial dosage optimization in patients with talaromycosis.

The high variability and unpredictability of the plasma concentration of voriconazole (VRC) pose a major challenge for clinical administration. The aim of this study was to develop a population pharmacokinetics (PPK) model of VRC and identify the factors influencing VRC PPK in patients with talaromycosis. Medical records and VRC medication history of patients with talaromycosis who were treated with VRC as initial therapy were collected. A total of 233 blood samples from 69 patients were included in the study. A PPK model was developed using the nonlinear mixed-effects models (NONMEM). Monte Carlo simulation was applied to optimize the initial dosage regimens with a therapeutic range of 1.0-5.5 mg/L as the target plasma trough concentration. A one-compartment model with first-order absorption and elimination adequately described the data. The typical voriconazole clearance was 4.34 L/h, the volume of distribution was 97.4 L, the absorption rate constant was set at 1.1 h-1, and the bioavailability was 95.1%. Clearance was found to be significantly associated with C-reactive protein (CRP). CYP2C19 polymorphisms had no effect on voriconazole pharmacokinetic parameters. Monte Carlo simulation based on CRP levels showed that a loading dose of 250 mg/12 h and a maintenance dose of 100 mg/12 h are recommended for patients with CRP ≤ 96 mg/L, whereas a loading dose of 200 mg/12 h and a maintenance dose of 75 mg/12 h are recommended for patients with CRP > 96 mg/L. The average probability of target attainment of the optimal dosage regimen in CRP ≤ 96 mg/L and CRP > 96 mg/L groups were 61.3% and 13.6% higher than with empirical medication, and the proportion of Cmin > 5.5 mg/L decreased by 28.9%. In conclusion, the VRC PPK model for talaromycosis patients shows good robustness and predictive performance, which can provide a reference for the clinical individualization of VRC. Adjusting initial dosage regimens based on CRP may promote the rational use of VRC.

Clinical and Histopathological Features of Congenital Fibrovascular Pupillary Membranes in a Chinese Case Series.

PURPOSE: To investigate the clinical and histopathological features of congenital fibrovascular pupillary membrane (CFPM) in Chinese patients. METHODS: This retrospective study reviewed CFPM cases treated at Beijing Children's Hospital. The clinical manifestations, approaches of treatment, outcomes, and histopathological findings were collected and analyzed. RESULTS: A total of 33 patients with CFPM were reviewed. All patients had unilateral eye involvement. A total of 21 eyes (63.64%) had a white membrane that partially covered the pupil and 12 eyes (36.36%) had a membrane that completely covered the pupil. Of the 12 eyes with a complete pupillary membrane, 6 (50%) had glaucoma. For eyes with a partial pupillary membrane, 11 eyes (52.38%) were followed up at the outpatient clinic without surgery and 10 eyes (47.62%) underwent membranectomy and pupilloplasty due to visual axis blockage. For the 12 eyes with a complete pupillary membrane, 6 eyes (50%) with normal intraocular pressure (IOP) received membranectomy and pupilloplasty combined with iridectomy, and 1 (16.67%) of these 6 eyes underwent a reoperation after 5 months due to a recurrent membrane. Furthermore, 6 eyes (50%) with glaucoma had membranectomy, pupilloplasty, iridectomy, and goniosynechialysis. Among these 6 eyes, 2 eyes (33.33%) underwent a reoperation due to the recurrence of a membrane and 4 eyes (66.67%) had a pale optic disc. The histopathological findings revealed that these membranes were mainly composed of fibrous tissue, lymphocytes, pigment epithelial cells, and vascular tissues. CONCLUSIONS: CFPM has diverse manifestations, including a partial pupillary membrane, a complete pupillary membrane with normal IOP, and a complete pupillary membrane with glaucoma. Timely diagnosis and treatment are critical when the visual axis is blocked and/or the IOP is high. [J Pediatr Ophthalmol Strabismus. 2021;58(2):105-111.].

Glaucoma secondary to congenital fibrovascular pupillary membrane: a single tertiary center experience.

We report the clinical features, treatments, and outcomes of 9 infants with glaucoma secondary to congenital fibrovascular pupillary membrane. The clinical features included unilateral low vision, high intraocular pressure (IOP), enlarged and cloudy cornea, loss of anterior chamber, and pupillary membrane. All patients underwent membranectomy, peripheral iridectomy, pupilloplasty, and goniosynechialysis as primary treatment. The membranes were posterior to the iris in all 9 eyes. In 5 eyes, the membrane covered the ciliary processes, and in 1 eye the membrane reached the posterior lens capsule. Following primary surgery, 3 patients developed membrane recurrence, 4 had refractory elevated IOP, and 2 developed lens opacities. All 4 eyes with poor postoperative IOP control had iris root insertion anterior to the scleral spur. Five patients received additional surgeries including membranectomy, pupilloplasty, goniosynechialysis, cyclocryotherapy, ciliary photocoagulation, Amhed valve implantation, and lensectomy. One patient had refractory elevated IOP at last follow-up. IOP in the other 8 eyes was well controlled. None of the affected eyes was able to fix and follow at last follow-up.

Outcomes of surgery for epiblepharon accompanied with lower eyelid retraction secondary to buphthalmos in children.

IMPORTANCE: In cases of epiblepharon with lower eyelid retraction secondary to glaucoma, correcting epiblepharon alone is ineffective. Combined surgery should be performed to obtain satisfactory outcomes. OBJECTIVE: To investigate outcomes after surgery to correct epiblepharon with lower eyelid retraction secondary to buphthalmos in children. METHODS: A retrospective analysis of six eyes in four patients was performed included lower lid retractor recession combined with marginal rotation with tarsal fixation. The margin reflex distance-2, lagophthalmus, resolution of clinical symptoms, and complications were assessed during 6 to 12 months of follow-up. RESULTS: In all cases, epiblepharon and lagophthalmus were corrected, symptoms of photophobia and epiphora were relieved, and the corneal epithelium was repaired. The margin reflex distance-2 decreased and remained normal during the follow-up period, but slightly regressed within 6 months postoperatively. INTERPRETATION: Epiblepharon caused by buphthalmos in children is often associated with lower eyelid retraction. Lower lid retractor recession combined with marginal rotation with tarsal fixation fundamentally solves the problems of high eyelid tension, lower eyelid retraction, and epiblepharon and reduces the recurrence rate.

A hierarchical deep learning approach with transparency and interpretability based on small samples for glaucoma diagnosis.

The application of deep learning algorithms for medical diagnosis in the real world faces challenges with transparency and interpretability. The labeling of large-scale samples leads to costly investment in developing deep learning algorithms. The application of human prior knowledge is an effective way to solve these problems. Previously, we developed a deep learning system for glaucoma diagnosis based on a large number of samples that had high sensitivity and specificity. However, it is a black box and the specific analytic methods cannot be elucidated. Here, we establish a hierarchical deep learning system based on a small number of samples that comprehensively simulates the diagnostic thinking of human experts. This system can extract the anatomical characteristics of the fundus images, including the optic disc, optic cup, and appearance of the retinal nerve fiber layer to realize automatic diagnosis of glaucoma. In addition, this system is transparent and interpretable, and the intermediate process of prediction can be visualized. Applying this system to three validation datasets of fundus images, we demonstrate performance comparable to that of human experts in diagnosing glaucoma. Moreover, it markedly improves the diagnostic accuracy of ophthalmologists. This system may expedite the screening and diagnosis of glaucoma, resulting in improved clinical outcomes.

A stick-slip piezoelectric actuator with high consistency in forward and reverse motions.

This paper presents a stick-slip piezoelectric actuator with high consistency in performances of forward and reverse motions. It is achieved by developing an integrated stator which bonds two lead zirconate titanate ceramic plates to a symmetrical flexible hinge mechanism. The working principle of the actuator was introduced, and the stator was optimized by finite-element analysis. Experimental results showed that the proposed actuator had an excellent consistency in output performances of forward and reverse motions with or without an external load. The positioning resolution, maximum speed, and maximum loading capacity of the actuator were 0.061 µm, 2195.29 µm/s, and 1.1 N, respectively. This study provides a solution for improving the forward and reverse motion consistency of stick-slip piezoelectric actuators.

[Necessity of defunctioning stoma in low anterior resection for rectal cancer: a meta-analysis].

OBJECTIVE: To evaluate the necessity of defunctioning stoma in low anterior resection for rectal cancer below peritoneal reflection. METHODS: The databases of Medline, Embase, Cochrane Library, Wanfang and CNKI were searched. The eligible studies were identified for pooled analyses. RESULTS: Six randomized controlled trials with 648 cases(332 patients with defunctioning stoma and 316 without stoma) and 25 retrospective controlled trials with 10,722 cases(4,470 patients with defunctioning stoma and 6,252 without stoma) were included. Combined analyses showed that defunctioning stoma was effective for decreasing risk of postoperative anastomotic leakage (RR=0.33 and 95% CI:0.21-0.53 for RCTs, OR=0.60 and 95% CI:0.42-0.85 for retrospective studies), reoperation (RR=0.30, 95% CI:0.16-0.53 for RCTs, OR=0.26 and 95% CI:0.21-0.32 for retrospective studies) and mortality(OR=0.41, 95% CI:0.27-0.62 for retrospective studies). CONCLUSION: Defunctioning stoma should be routinely performed in low anterior resection for high-risk patients.