Study on the difference of high frequency dielectric properties of biological tissues measured by air and packed coaxial probe / 生物医学工程学杂志

In this paper, the differences between air probe and filled probe for measuring high-frequency dielectric properties of biological tissues are investigated based on the equivalent circuit model to provide a reference for the methodology of high-frequency measurement of biological tissue dielectric properties. Two types of probes were used to measure different concentrations of NaCl solution in the frequency band of 100 MHz-2 GHz. The results showed that the accuracy and reliability of the calculated results of the air probe were lower than that of the filled probe, especially the dielectric coefficient of the measured material, and the higher the concentration of NaCl solution, the higher the error. By laminating the probe terminal, liquid intrusion could be prevented, to a certain extent, to improve the accuracy of measurement. However, as the frequency decreased, the influence of the film on the measurement increased and the measurement accuracy decreased. The results of the study show that the air probe, despite its simple dimensional design and easy calibration, differs from the conventional equivalent circuit model in actual measurements, and the model needs to be re-corrected for actual use. The filled probe matches the equivalent circuit model better, and therefore has better measurement accuracy and reliability.

Research advances of 3D printing in vascularization / 口腔医学

@#As the key to regeneration of oral and maxillofacial tissues such as bone, dental pulp and skin, vascularization has always been the focus of tissue engineering. With the development of three-dimensional (3D) printing in tissue engineering, there are increasing ways to construct vascular structures. However, to achieve the objective of highly simulating vascular structure in morphology and function and promote tissue repair, it is still a major difficulty for 3D bioprinting to construct highly precise and biologically functional simulated vascular structures. This paper summarizes new progress of 3D printing vascular structure, expounds frontier biological manufacturing technologies of vascular and vascularized structure such as suspension printing, coaxial printing, 4D printing, and so on, analyzes its advantages and disadvantages, and discusses its development prospect, in order to provide reference for the application of 3D printing blood vessels in regeneration and repair of oral and maxillofacial tissues.

Nuevos factores de riesgo de hemorragia pulmonar que complican la biopsia pulmonar guiada por TC en técnica coaxial / Novel risk factors of pulmonary hemorrhage complicating CT-guided lung biopsy in coaxial technique

Objetivos: Evaluar la frecuencia y gravedad de la hemorragia parenquimatosa pulmonar tras la biopsia pulmonar con aguja transtorácica coaxial, según factores de procedimiento, aún no descritos en la literatura. El objetivo de este estudio fue determinar si la elección de la tecnología de biopsia coaxial, el posicionamiento del paciente y la dignidad de la lesión son tres nuevas variables que influyen en el riesgo de hemorragia parenquimatosa tras biopsias coaxiales de pulmón. Métodos: Se revisaron retrospectivamente los registros de 117 pacientes que se sometieron a biopsias con aguja transtorácica del pulmón entre enero de 2018 y abril de 2020. El resultado primario fue la hemorragia pulmonar. Se ha utilizado un sistema de clasificación para clasificar la hemorragia parenquimatosa pulmonar: Grado 0 - Grado 3. Se evaluaron tres variables novedosas relacionadas con el paciente, la técnica y la lesión como predictores de hemorragia pulmonar: tecnología de biopsia coaxial, posición del paciente y dignidad de la lesión. Resultados: De los 117 pacientes, 18 (15,4%) pacientes con tecnología de biopsia coaxial de corte, versus 29 (24,8%) pacientes con tecnología coaxial de núcleo completo mostraron hemorragia significativa en las exploraciones de control posteriores a la biopsia. (IC del 95% 0,06-0,33, p <0,0001). No hubo diferencias significativas en la hemorragia pulmonar entre el diagnóstico histológico benigno y maligno (IC 95% 0,84-4,44, p = 0,1199) y la posición del paciente en decúbito prono o supino (IC 95%: 0,57-2,57, p = 0,6232). Conclusiones: La incidencia y gravedad de la hemorragia pulmonar depende de la tecnología de biopsia coaxial utilizada; siendo mayor en pacientes sometidos a una biopsia con tecnología full-core y menor después del uso de tecnología de corte. En este estudio de pronóstico no se estableció una correlación significativa entre la hemorragia pulmonar parenquimatosa y la posición del paciente o la dignidad de la lesión

Objectives: To evaluate the frequency and severity of pulmonary parenchymal hemorrhage after coaxial transthoracic needle biopsy of the lung, according to procedural factors, not yet described in literature. The aim of this study was to determine whether the choice of the coaxial biopsy technology, patient positioning and the lesion dignity are three new variables influencing the risk of parenchymal hemorrhage after coaxial biopsies of the lung. Methods: Records from 117 patients who underwent transthoracic needle biopsies of the lung between January 2018 and April 2020 have been retrospectively reviewed. The primary outcome was pulmonary hemorrhage. A grading system has been used to classify pulmonary parenchymal hemorrhage: Grade 0 ­ Grade 3. Three novel patient, technique and lesion-related variables were evaluated as predictors of pulmonary hemorrhage: coaxial biopsy technology, patient positioning and lesion dignity. Results: Out of the 117 patients, 18 (15,4%) patients with cutting coaxial biopsy technology, versus 29 (24,8%) patients with full core coaxial technology showed significant hemorrhage on the post-biopsy control scans. (95% CI 0,06-0,33, p<0,0001). No significant difference in pulmonary hemorrhage between benign and malignant histological diagnosis (95% CI 0,84-4,44, p=0,1199) and prone or supine patient positioning (95% CI: 0,57-2,57, p= 0,6232) was found. Conclusions: The incidence and severity of pulmonary hemorrhage depends on the coaxial biopsy technology used; being higher in patients undergoing a biopsy with full-core technology and lower after the use of cutting technology. No significant correlation between parenchymal pulmonary hemorrhage and patient positioning or lesion dignity was established in this prognostic study.

Coaxial needle technology for pain control during ultrasound-guided transperineal prostate biopsy: a prospective, randomized, controlled trial / 中华超声影像学杂志

Objective:To investigate the feasibility, effectiveness and safety of ultrasound-guided transperineal prostate biopsy (TPB) with coaxial needle technique, and to improve the pain perception of TPB patients by reducing the number of direct perineal needling.Methods:A total of 200 patients who underwent ultrasound-guided TPB at the first clinical college of Three Gorges University & Yichang Central People′s Hospital from January 2019 to December 2020 were randomly divided into coaxial needle group (coaxial needle positioning puncture, n=100) and traditional group (traditional puncture frame guided repeated transperineal puncture, n=100). Visual analog scale (VAS) was used to evaluate the pain of patients during puncture. The number of samples, time-consuming of puncture, cancer detection rate, VAS pain score and complications between the two groups were compared. Results:The success rate of puncture in the coaxial needle group and the traditional group was 100%, and there was no significant difference in the cancer detection rate between the two groups (48% vs 40%, P>0.05). The average number of samples in the coaxial needle group was larger than that in the traditional group, the average puncture time in the coaxial needle group was less than that in the traditional group, and the average intraoperative VAS score of the coaxial needle group was lower than that of the traditional group, the differences were statistically significant[(14.8±1.8) vs (12.1±1.1), (12.9±1.3)min vs (16.5±1.9)min, (2.6±1.2) vs (4.4±1.4); all P<0.001]. The complication rate of the coaxial needle group was lower than that of the traditional group, the difference was statistically significant (18% vs 39%, P<0.001), the incidences of perineal hematoma and perineal pain in the coaxial needle group were lower than that in the traditional group (1% vs 8%, 8% vs 19%; all P<0.05). Conclusions:Coaxial needle technology for ultrasound-guided TPB can ensure the number of samples and accurate sampling in different areas, significantly reduce the number of direct perineal puncture, improve the pain in the process of puncture, reduce the incidence of postoperative perineal pain, with shorter operation time and fewer complications, which is worthy of clinical promotion.

Development of a predictive model of pulmonary hemorrhage in patients after CT-guided coaxial core needle lung biopsy / 西安交通大学学报(医学版)

【Objective】 To establish a predictive model for patients with hemorrhage after CT-guided coaxial core needle lung biopsy （CCNB） based on logistic regression. 【Methods】 A total of 489 patients who had undergone CCNB were retrospectively recruited. The potential risk factors of hemorrhage after lung biopsy were analyzed by univariate and multivariate logistic regression， through which we screened the independent risk factors and established a prediction model for hemorrhage. We evaluated the discrimination， calibration and clinical usefulness of the model. 【Results】 There were 141 cases （42.6%） of hemorrhage in the development group and 66 cases （41.8%） of hemorrhage in the validation group； there was no case of severe hemorrhage or hemothorax. Multivariate logistic regression analysis showed that fibrinogen degradation products， pulmonary interstitial fibrosis， largest diameter and puncture depth were independent predictive factors of hemorrhage. Hemorrhage prediction model was established and presented in the form of a nomogram. Discrimination of the model： the AUC was 0.837 in the development group and 0.777 in the validation group. The calibration curve showed good agreement between predicted probability and actual probability of hemorrhage. The unreliability test yielded a P value of 0.849 in the development group and 0.147 in the validation group. The DCA curve showed that the hemorrhage predictive model could increase the benefit of patients. 【Conclusion】 The predictive model of hemorrhage in patients after CCNB based on logistic regression can be used in clinical practice.

Synchronous core-needle biopsy and microwave ablation for highly suspicious malignant pulmonary nodule via a coaxial cannula

Aims: This study aimed to evaluate the safety and feasibility of computed tomography (CT)-guided synchronous percutaneous core-needle biopsy and microwave ablation (MWA) for highly suspicious malignant pulmonary nodules. Materials and Methods: This retrospective study evaluated medical records of 54 consecutive patients (mean age, 65.5 ± 11.2 years) with 62 highly suspicious malignant pulmonary nodules who synchronously underwent percutaneous core-needle biopsy and MWA via a coaxial cannula (Group A) or sequentially underwent these procedures (Group B) from September 2016 to November 2017. All patients were followed up for at least 6 months after MWA. The safety and feasibility of synchronous core-needle biopsy and MWA were analyzed by comparing clinical data, technical success rate, complication, and curative effect per nodule with those of sequential procedures. Results: Technical success rates were 100% in both groups. The pneumothorax rate was 29.6% (8/27) in Group A and 57.1% (20/35) in Group B, which was statistically different (P = 0.031). In Group A, hemoptysis and pleural effusion rates were 22.2% (6/27), and in Group B, the corresponding rates were 28.6% (10/35) and 20.0% (7/35), respectively. No postprocedural pulmonary artery pseudoaneurysm, bronchopleural fistula, or needle-tract tumor seeding developed in both groups. After 6 months' follow-up, the effective rates (complete + partial response) in both groups were 100%. Conclusions: Synchronous core-needle biopsy and MWA via a coaxial cannula is technically safe and feasible in the management of highly suspicious malignant pulmonary nodules, and this procedure has lesser complications and similar effects (both 100% effective treatment) compared with sequential procedures

Sensing volume of tissue dielectric property measurement with open-ended coaxial probe / 南方医科大学学报

OBJECTIVE@#To investigate the sensing volume of open-ended coaxial probe technique for measurement of dielectric characteristics.@*METHODS@#A measurement model combining macro- measurement device with a layer model of dielectric properties parameters was established for evaluating the sensing volume of open-ended coaxial probe technique. We defined sensing depth and sensing diameter to describe the distance that could be detected in vertical and horizontal direction. Using a variety of materials with different dielectric properties (Teflon, deionized water, ethanol, and gradient concentration sodium chloride solution), a layered model of dielectric properties differentiation was established. The total combined uncertainties (TCU) were calculated for different output power, and the output power was controlled to increase from -50 dBm to 15 dBm to calibrate the error range of the dielectric properties measurement system. The optimal output power range was determined based on the results of TCU test. In sensing volume measurement experiment, we set the control groups based on measurement parameters that potentially affect the sensing volume including output power (-10, -5, 0, 3, 6, and 9 dBm), frequency (1-500 MHz), Teflon, deionized water, and ethanol to form a dielectric constant difference between high and low contrast groups. Different concentrations of sodium chloride solution and Teflon were used to generate a conductivity difference between high and low contrast groups. These groups were tested in the sensing depth and sensing diameter measurement experiments.@*RESULTS@#The result of TCU test indicated that accurate and stable measurement results could be obtained when the output power was greater or equal to-10 dBm (TCU < 2%). Sensing volume measurement experiment revealed a positive correlation between the sensing depth and output power ( < 0.05). As the measured power increased, the sensing depth gradually increased in deionized water and ethanol, and the difference reached 70 μm. The sensing depth was negatively correlated frequency ( < 0.05). As the concentration of sodium chloride solution increased, the corresponding sensing depth gradually decreased, with a difference reaching 270 μm. The sensing depth of high dielectric materials was greater than that pf low dielectric materials. The results of sensing diameter measurement were not obviously affected by the measurement parameters, and the sensing diameter was stable in a fixed range (1.0 to 1.8 mm) between the diameter of the inner conductor and the diameter of the insulation layer, and was less than the diameter of the probe.@*CONCLUSIONS@#The sensing volume of open-ended coaxial probe technique is affected by measurement parameters and dielectric properties of materials, which significantly affect the sensing depth.

Optimization of the coaxial cell printing performance of bioink and printing of tissue-engineered scaffolds with vascular-like structure / 中国组织工程研究

BACKGROUND: Cells cannot survive in the area 200 µm away from nutrients in vitro. Vascular network construction is crucial for thick tissue and organ regeneration in tissue engineering. Coaxial cell printing provides a new way to construct vascular-like channels in vitro. OBJECTIVE: To optimize the coaxial cell printing performance of bioink and to build the tissue-engineered scaffolds with vascular-like structure. METHODS: The aseptic sodium alginate solution was prepared by intermittent pasteurization and then frozen. Freeze-dried powder of aseptic silk fibroin was prepared from degummed silk and sealed. The thawed sodium alginate solution was added to the silk fibroin protein freeze-dried powder and human umbilical vein endothelial cells were added to prepare the bioink. The outer axis of the biological three-dimensional printer was connected with the bioink, and the inner axis was connected with the crosslinking agent. The scaffolds were prepared by coaxial printing, and performed by optical coherence tomography, scanning electron microscopy observation and tensile test. Coaxial scaffolds were made by freeze-preserved sodium alginate solution for 7 days with human umbilical vein endothelial cells. Coaxial scaffolds were also made by freeze-dried sodium alginate solution for 7 days with human umbilical vein endothelial cells and silk fibroin protein sealed for 6 months. The cell survival rate was detected by dead and alive staining after 24 hours of culture in vitro. Vascular-like scaffolds with series and parallel structures were designed and printed. The cell proliferation was detected after 1, 3, 7, 10, and 14 days of culture. RESULTS AND CONCLUSIONS: (1) The optical coherence tomography showed that the maximum printing height of the bioink was 9 layers and the overall thickness was about 4.4 mm. Scanning electron microscopy showed that the outer wall of hollow fiber-filament of vascular-like scaffolds presented irregular strip-shaped crimp with micron-scale internal connected pore structure, while the inner wall of hollow fiber-filament had denser pore structure. (2) The elastic modulus of silk protein freeze-dried scaffold was higher than that of sodium alginate solution (P < 0.05). (3) The cell survival rate of scaffolds treated with sodium alginate solution for 7 days was (86.7±3.4)%, and that of scaffolds treated with silk protein freeze-dried powder for 7 days was (98.1±1.2)%, indicating that the sodium alginate solution freeze- preserved for 7 days was free of bacteria and the shelf-life of silk protein could be up to 6 months. (4) The proliferation activity of cells cultured with parallel structure for 7, 10, and 14 days was higher than that with series structure (P < 0.05). (5) These results imply that the scaffolds have good biocompatibility and mechanical properties.

VPA/PLGA microfibers produced by coaxial electrospinning for the treatment of central nervous system injury

The central nervous system shows limited regenerative capacity after injury. Spinal cord injury (SCI) is a devastating traumatic injury resulting in loss of sensory, motor, and autonomic function distal from the level of injury. An appropriate combination of biomaterials and bioactive substances is currently thought to be a promising approach to treat this condition. Systemic administration of valproic acid (VPA) has been previously shown to promote functional recovery in animal models of SCI. In this study, VPA was encapsulated in poly(lactic-co-glycolic acid) (PLGA) microfibers by the coaxial electrospinning technique. Fibers showed continuous and cylindrical morphology, randomly oriented fibers, and compatible morphological and mechanical characteristics for application in SCI. Drug-release analysis indicated a rapid release of VPA during the first day of the in vitro test. The coaxial fibers containing VPA supported adhesion, viability, and proliferation of PC12 cells. In addition, the VPA/PLGA microfibers induced the reduction of PC12 cell viability, as has already been described in the literature. The biomaterials were implanted in rats after SCI. The groups that received the implants did not show increased functional recovery or tissue regeneration compared to the control. These results indicated the cytocompatibility of the VPA/PLGA core-shell microfibers and that it may be a promising approach to treat SCI when combined with other strategies.

Clinical analysis of two different incisions of coaxial phacoemulsification / 国际眼科杂志(Guoji Yanke Zazhi)

·AIM: To compare the clinical effects of 2.2mm coaxial micro-incision and 3.0mm standard incision in cataract phacoemulsification surgery. ·METHODS: A total of 67 patients (80 eyes) were randomly divided into two groups. Cataract phacoemulsification and artificial lens implantation surgery was carried out with 2. 2mm coaxial micro -incision (Group A, 40 eyes) and 3. 0 mm standard incision(Group B, 40 eyes), respectively. The effective phacoemulsification time and average ultrasound energy, corneal endothelial cell count, corneal edema, corneal astigmatism, postoperative visual acuity and postoperative complications were compared between the two groups. ·RESULTS: Effective phacoemulsification time of Group A and Group B was 8. 18 ± 11. 22s and 7. 82 ± 2. 12s, respectively, and the difference had no statistical significance(P> 0. 05); average ultrasonic energy was (17.25 ± 4.22)% and (17.64 ± 4.27)%, respectively, and the difference was not statistical significance(P>0.05). There was no significant difference in endothelial cells between the two groups of corneal endothelial cells at 1wk after surgery compared with that before operation (P>0.05). On the first day after surgery, corneal edema was observed in some patients. There were 9 eyes in Group A,6 eyes in Group B,corneal edema relief or subsidence after 3d to 5d. There was significant difference in corneal astigmatism change between the two groups at 1wk (P<0.05), but there was no significant difference at 1 and 3mo after operation (P>0.05). The changes of corneal astigmatism before and after operation in Group A were insignificant (P>0. 05), while the changes of corneal astigmatism before and after operation in Group B were significantly different (P< 0. 05). At 1 and 3mo after operation, the astigmatism of each group tended to be stable, and the corneal astigmatism in the two groups after 1 and 3mo had no statistical significant difference (P> 0. 05). The uncorrected visual acuity (UCVA) differences of the two groups was statistically significant at 1d,1wk and 1mo after operation (P<0.05), but there was no significant difference between the two groups in UCVA after 3mo (P>0.05). ·CONCLUSION: For soft or medium - hard nucleus cataract, compared with the traditional 3. 0mm small-incision coaxial phacoemulsification, the 2.2mm micro-incision coaxial phacoemulsification can effectively reduce the surgically induced astigmatism, and the astigmatism state is relatively stable, and conducive to early recovery of visual acuity.

The clinical application of CT-guided percutaneous coaxial needle biopsy combined with microwave ablation for lung tumors / 介入放射学杂志

Objective To evaluate the effect of CT-guided percutaneous coaxial needle biopsy combined with microwave ablation (MWA) for the treatment of lung tumors, and to discuss its technique, safety, curative effect and clinical application value. Methods A total of 20 patients with lung tumor, who were admitted to the Department of Interventional Radiology, Shanghai Ruijin Hospital, China, during the period from August 2014 to June 2016, were collected. Among the 20 patients, primary pulmonary cancer was diagnosed in 9 and metastatic tumor in 11. A total of 23 tumor lesions were detected, and CT-guided percutaneous coaxial needle biopsy combined with MWA was performed for all lesions. Based on the size and shape of the tumor, the corresponding ablation power and time of duration were set up. After the treatment, the patients were followed up for 4-26 months, and chest enhanced CT examination was regularly reexamined to assess the curative effect. Results Percutaneous coaxial needle biopsy was carried out for 23 lesions, the tumor diameters ranged from 0.80 cm to 2.40 cm, with a mean of 1.39 cm. MWA was employed for 23 lesions. CT scan performed immediately after MWA showed that the density of tumor lesion became decreased, the diagnostic positive rate of needle biopsy was 83.3％. After the treatment, complete remission was obtained in 15 patients, partial remission in 2 patients, stable disease in one patient, and progression.

3D biofabrication of vascular networks for tissue regeneration: A report on recent advances / 药物分析学报

Rapid progress in tissue engineering research in past decades has opened up vast possibilities to tackle the challenges of generating tissues or organs that mimic native structures. The success of tissue en-gineered constructs largely depends on the incorporation of a stable vascular network that eventually anastomoses with the host vasculature to support the various biological functions of embedded cells. In recent years, significant progress has been achieved with respect to extrusion, laser, micro-molding, and electrospinning-based techniques that allow the fabrication of any geometry in a layer-by-layer fashion. Moreover, decellularized matrix, self-assembled structures, and cell sheets have been explored to replace the biopolymers needed for scaffold fabrication. While the techniques have evolved to create specific tissues or organs with outstanding geometric precision, formation of interconnected, functional, and perfused vascular networks remains a challenge. This article briefly reviews recent progress in 3D fab-rication approaches used to fabricate vascular networks with incorporated cells, angiogenic factors, proteins, and/or peptides. The influence of the fabricated network on blood vessel formation, and the various features, merits, and shortcomings of the various fabrication techniques are discussed and summarized.

Treatment and postoperative effects of coaxial micro-incision phacoemulsification on patients with cataract / 国际眼科杂志(Guoji Yanke Zazhi)

@#AIM: To analyze the clinical efficacy and postoperative impacts of coaxial micro-incision phacoemulsification on patients with cataract, and explore the application value of the surgical method. <p>METHODS: Totally 300 patients(300 eyes)who received the coaxial micro-incision phacoemulsification were randomly divided into the observation group(150 case)and the control group(150 case). Patients in the observation group and control group were treated by coaxial micro-incision phacoemulsification and traditional coaxial phacoemulsification, respectively. The effective phaco time(EPT), average ultrasound energy(AVE), intraoperative anterior chamber stability and postoperative recovery time were compared between the two groups, as well as the uncorrected visual acuity(UCVA), the surgically induced astigmatism(SIA)and the loss rate of corneal endothelial cells at 1d, 1wk, 1 and 3mo after surgery. <p>RESULTS: No significant difference of EPT, AVE and the rate of patients with stable anterior chamber were found between the two groups(<i>P</i>>0.05), as well as the UCVA, SIA and the corneal endothelial cells in patients before surgery(<i>P</i>>0.05).The postoperative recovery time of patients in the observation group was obviously shorter than that in the control group(<i>P</i><0.05). At 1d, 1wk and 1mo of postoperative, the UCVA of patients in the observation group were better than those in the control group(<i>P</i><0.05). In 1wk, 1 and 3mo of postoperative, the SIA of patients in the observation group were lower than those in the control group(<i>P</i><0.05). And in all the time of postoperative, the loss rate of corneal endothelial cells of patients in the observation group were lower than those in the control group(<i>P</i><0.05). Between the two groups, significant difference of the UCVA, SIA and the loss rate of corneal endothelial cells were found in the different time points after surgery(<i>P</i><0.05). <p>CONCLUSION: The coaxial micro-incision phacoemulsification had a high clinical value as it possesses the advantages of more rapid UCVA recovery, less influence on SIA and less loss of corneal endothelial cell.

Effect of cataract surgical incision on original astigmatism and tear film stability of corrected cornea / 国际眼科杂志(Guoji Yanke Zazhi)

AIM:To investigate the effect of the size of cataract surgical incision on original astigmatism and tear film stability of corrected cornea.METHODS: Totally 92 cataract patients (92 eyes) who were admitted to our hospital from July 2014 to July 2016 were randomly divided into the control group and the observation group,46 cases (46 eyes) in each group.Both groups were treated by clear corneal tunnel incision phacoemulsification combined with intraocular lens implantation.The incision of the control group was 3.0mm while of the observation group was 1.8mm.The uncorrected visual acuity,corneal astigmatism,Schirmer I test (SⅠt) and break-up time (BUT) were detected before surgery and at 1d,1wk,1mo and 3mo after surgery.The surgery induced astigmatism (SIA) was recorded at 1d,1wk,1 and 3mo after surgery.RESULTS: There were significant differences in the uncorrected visual acuity between the two groups at 1 and 3mo before surgery (P0.05).At 1wk,1 and 3mo after surgery,SIA of two groups decreased continuously,and the SIA of the observation group was significantly lower than that of the control group at 1d,1wk and 1mo after surgery (P0.05).SⅠt and BUT in the observation group were less or shorter than those in the control group at 1wk after surgery (P0.05).CONCLUSION: Compared with 3.0mm standard incision,1.8mm clear corneal incision can reduce SIA and shorten the time for corneal stability recovery.

Changes of the ocular surface and tear film after the coaxial incision 2.5mm and 3.0mm in the phacoemulsification / 国际眼科杂志(Guoji Yanke Zazhi)

AIM:To study the changes of tear film and ocular surface after the coaxial incision 2.5mm and 3.0mm in the phacoemulsification.METHODS: Seventy patients (92 eyes) from February 2015 to February 2016 in our hospital were enrolled.The patients were randomly divided into two groups.Thirty-four patients (46 eyes) in Group A: coaxial 2.5mm incision phacoemulsification cataract extraction and intraocular lens(IOL) implantation.Thirty-six patients (46 eyes) in Group B: the conventional coaxial 3.0mm small incision phacoemulsification cataract extraction and IOL implantation.The break up time (BUT),Schirmer`s Ⅰ test (SⅠt) and lid-parallel conjunctival folds (LIPCOF) were assessed preoperatively and postoperatively.RESULTS: At 1wk,1 and 3mo postoperatively,the BUT in two groups decreased after operations,and the BUT of Group B was significantly lower than those of Group A,the differences were statistically significant (t=3.089,4.497,4.322;all P0.05).The BUT,SⅠt and LIPCOF score in Group B showed statistically significant differences (t=-4.059,3.629,4.211;all P<0.05).CONCLUSION: Ocular surface has less damage and tear film has little influence at early stage after the coaxial 2.5mm incision phacoemulsmcation,compared with the conventional coaxial 3.0mm incision phacoemulsification surgery.

Comparison of effect of two different -incision phacoemulsifications in the treatment of cataract / 国际眼科杂志(Guoji Yanke Zazhi)

AIM:To explore and compare effect of coaxial micro-incision phacoemulsification and standard coaxial phacoemulsification in the treatment of cataract. METHODS:A total of 88 patients(88 eyes) with senile cataract who underwent selective cataract ultrasonic emulsification resorption combined with intraocular lens implantation in the hospital from Aug. 2013 and Aug. 2015 were selected, they were divided randomly into the control group ( 44 cases, 38 cases completed, 6 cases dropped out ) and the observation group ( 44 cases, 40 cases completed, 4 cases dropped out ) . The control group received standard coaxial 3. 0mm small incision phacoemulsification, the observation group received coaxial 1. 8mm micro-incision phacoemulsification. All patients were combined with intraocular lens implantation. Intraoperative effective ultrasonic time, cumulative release energy, best corrected visual acuity before and after surgery in the two groups were recorded, corneal endothelium cell population, incision corneal thickness, percentage of cornea hexagon cell, corneal astigmatism changes before the operation, 1d, 7d, 30d after the operation were compared. RESULTS: There was no significant difference in intraoperative effective ultrasonic time, cumulative release energy in the two groups(P>0. 05). There was no significant difference in postoperative best corrected visual acuity between the two groups(P>0. 05). Corneal endothelium cell population, percentage of cornea hexagon cell 1d, 7d, 30d after the operation in the two groups were significantly decreased compared with those before the treatment ( P 0. 05 ). Incision corneal thickness 30d after the operation in the observation group was significantly lower than the control group(PCONCLUSION: Coaxial micro - incision phacoemulsification and standard coaxial phacoemulsification can improve visual acuity of cataract patients, but the former can reduce degree of corneal astigmatism.

Changes of the ocular surface and tear film after the coaxial micro incision 2 . 2 mm and 2 . 8 mm in the phacoemulsification / 国际眼科杂志(Guoji Yanke Zazhi)

AIM:To study the changes of tear film and ocular surface after the coaxial micro incision 2. 2mm and 2. 8mm in the phacoemulsification. METHODS:Eighty-six patients ( One hundred and six eyes ) from 2014/06 to 2016/01 in our hospital were enrolled. The patients were randomly divided into two groups. Forty-four patients ( Fifty-three eyes) in group A: coaxial 2. 2mm micro- incision phacoemulsification cataract extraction and intraocular lens(IOL) implantation;Forty-two patients ( Fifty-three eyes ) in group B: the conventional coaxial 2. 8mm small incision phacoemulsification cataract extraction and IOL implantation. The break up time ( BUT) , dry eye symptom ( DES) score, Schirmer's I test ( SⅠt ) and lid-wiper epitheliopathy ( LWE ) score were assessed preoperatively and postoperatively. RESULTS:At 1wk, 1 and 2mo postoperatively, the BUT in two groups decreased after operations, and the BUT of group B was significantly lower than those of group A, the differences were statistically significant ( t = 3. 098, 4.512, 4.329; all P 0. 05). The BUT, DES score, SⅠt and LWE score in group B showed statistically significant differences (t=-4. 063, 7. 306, 3. 621, 4. 208;all P<0. 05).CONCLUSION:Ocular surface has less damage and tear film has little influence at early stage after the coaxial 2.2mm microincision phacoemulsification, compared with the conventional coaxial 2. 8mm incision phacoemulsification surgery.

Research on Thin Film type Hydrogen Sulfide Sensor Based on SnO2-CuO Nanofibers / 分析化学

A SnO2-CuO composite nanofiber was prepared by the coaxial electrospinning method. A new thin-film-type hydrogen sulfide gas sensor was designed by coating SnO2-CuO composite nanofibers onto an alumina ceramic tube with Au electrodes by dip-coating method. The crystalline phase and microstructure of SnO2-CuO composite nanofibers were characterized using X-ray diffraction ( XRD ) and scanning electron microscope ( SEM) . The influence of chemical composition and thickness of sensitive film on the sensitive mechanism and electrochemical characteristic of SnO2-CuO nanofibers were analyzed. The characteristic tests of hydrogen sulfide sensor including sensitive performance, temperature, relative humidity, dynamic response, interference and stability were carried out by WS-30A type multifunction analyzer in gas sensor test system. The results demonstrated that, when the operating temperature was 25℃ and hydrogen sulfide gas concentration increased from 10 to 60 mg/L, the hydrogen sulfide sensor based on C50 composite nanofibers with 70 nm sensitive film thickness had the best linearity (92. 3%) and sensitivity (98. 2%). Besides, its highest response values and relatively humidity level were 1080 and 95%, respectively, and its dynamic response time and recover time were 4 s and 12 s, respectively. This sensor showed good anti-disturbance to the gases, such as CO, NO2 , SO2 , NH3 , CO2 , CH4 and H2 . The response value of the sensor was attenuated about 9. 2% when it was applied continually in the mine about 12 months, and its normal response time was 10. 9 months.

The open-ended coaxial line method for colorectal cancer detection and depth evaluation of tumor invasion / 实用医学杂志

Objective To confirm whether the open-ended coaxial line is effective in detection of the differences in dielectric properties between colorectal cancer tissues and surrounding normal tissues and evaluation of the depth of tumor invasion. Methods The open-ended coaxial line system at frequencies ranging from 50 to 500 MHz in 98 freshly excised colorectal cancerous specimens obtained from the operating theatre of Zhujiang Hospital, was used to detect both the relative permittivity and conductivity on the serosal surface of the carcinoma nidus, the mucosa of the carcinoma nidus, and the mucosa of the surgical resection margin. Pathological examinations were conducted on each specimen after surgery. Results The values for relative permittivity and conductivity of the colorectal cancerous mucosa were significantly higher than those of the normal mucosa (P < 0.01). For the tumor which had invaded or penetrated the serosa (stage ≥ T3), the dielectric properties of both the cancerous serosa and mucosa were higher than the one restricted to muscularis propria or less intestine wall (stage < T3) over the measured frequency range, and there existed statistical differences at the common frequencies of 213 MHz and 426 MHz. Conclusion The open-ended coaxial line system may result in fast and effective diagnostic differentiation between cancerous and normal colorectal tissues as well as reasonable assessment of the tumor infiltration depth.

Preparation of asiaticoside-loaded coaxial and composite nanofibers and their sustained-release effects / 国际药学研究杂志

Objective To prepare asiaticoside- loaded coaxial and composite nanofibers using the electrospinning method, evaluate their morphologies and drug release, and provide a novel functional wound dressing for deep partial- thickness burn injury. Methods Formulations and preparation methods of asiaticoside- loaded coaxial nanofibers were explored, involving the concentrations of various polymers in the shell and core, and electrospinning conditions. The nanofibers were characterized with scanning electron microscopy, transmission electron microscopy, and X-ray diffraction. Drug release of them was investigated. Results The optimal formulation of the asiaticoside-loaded coaxial nanofibers was as follows: the mixture of 0.8% sodium alginate and 7% polyvinyl alcohol as the shell solution, and 3% chitosan solution containing 2.5% asiaticoside as the core solution. The optimal preparation condition was as follows: the static voltage of 23 kV, the injector tip-collector distance of 15 cm, 0.8 ml/h and 0.2 ml/h injecting rates for the shell solution and core solution, respectively. The composite nanofibers were prepared with a similar method to the coaxial nanofibers. The coaxial nanofibers obviously showed the core- shell structure with the core diameter of 99.2 nm and the fiber diameter of 166.8 nm. The coaxial nanofibers showed drug sustained release compared with the composite nanofibers and the Fick′s diffusion dominated. Conclusion The coaxial nanofibers obviously showed drug sustained release, favoring the wound healing effect of asiaticoside. The coaxial nanofibers would a novel functional wound dressing for the treatment of deep partial-thickness burn injury.