Design, modeling, and testing of a one degree of freedom manipulator with three-stage amplification mechanism

The one degree of freedom (1-DOF) manipulator with nano-resolution is a significant component in the micro-/nano-manipulation. In order to simultaneously achieve a large stroke and high precision, a piezo-driven 1-DOF flexure-based manipulator consisting of an enhanced double Scott-Russell mechanism (EDSRM), a lever type mechanism, and a Z-shaped mechanism is proposed in this paper. Analytical models are developed to examine the kinetostatic and dynamic properties of the manipulator. A finite element analysis is further performed to evaluate the characteristics of the EDSRM and the complete manipulator. The prototype is fabricated on monolithic AL7075, and various experimental tests have been carried out to investigate the correctness of the modeling. The experimental results show that the proposed manipulator has a satisfactory amplification ratio, static stability, and dynamic performance.

[Application of retroauricular sulcus incision in surgery of parotid gland tumor]

Objective: To investigate the application of retroauricular sulcus incision in surgery for benign tumor in superficial lobe of parotid gland. Methods: A total of 20 patients were reviewed who underwent the resection of benign tumor in the superficial lobe of parotid gland with retroauricular sulcus incision at the Department of Otorhinolaryngology, the Linyi City People Hospital between May 2015 and March 2017. There were 12 males and 8 females with an age range of 12-66 years old, including 15 cases with mixed tumor and 5 cases with adenolymphoma. Surgical procedure included facial never dissection from the main trunk to facial never cervical trunk, temporal trunk and peripheral branches. After resection of tumor and superficial lobe of parotid gland, and sternocleidomastoid muscle flap was used to fill the defect in parotid area. All patients were postoperatively followed up after surgery. Results: Surgeries were successfully operated in all patients. Follow-up for 2 years showed there was no presence of recurrence, salivary fistula, Frey syndrome, scar affecting facial appearance, or significant deformity in the surgical area. Conclusion: Surgery for superficial lobe of parotid gland and facial nerve dissection through retroauricular sulcus incision have some advantages such as incision concealment, simple procedure for facial nerve dissection, simultaneous repair of tissue defects with sternocleidomastoid muscle flap, and less complications.

[Human selenium-containing single-chain variable fragment with glutathione peroxidase activity protects NIH3T3 fibroblast against oxidative damage]

Ultraviolet B (UVB medium wave, 280-315 nm) induces cellular oxidative damage and apoptosis by producing reactive oxygen species (ROS). Glutathione peroxidase functions as an antioxidant by catalyzing the reduction of hydrogen peroxide, the more important member of reactive oxygen species. A human selenium-containing single-chain variable fragment (se-scFv-B3) with glutathione peroxidase activity of 1288 U/μmol was generated and investigated for its antioxidant effects in UVB-induced oxidative damage model. In particular, cell viability, lipid peroxidation extent, cell apoptosis, the change of mitochondrial membrane potential, caspase-3 activity and the levels of intracellular reactive oxygen species were assayed. Human se-scFv-B3 protects NIH3T3 cells against ultraviolet B-induced oxidative damage and subsequent apoptosis by prevention of lipid peroxidation, inhibition of the collapse of mitochondrial membrane potential as well as the suppression of the caspase-3 activity and the level of intracellular ROS. It seems that antioxidant effects of human se-scFv-B3 are mainly associated with its capability to scavenge reactive oxygen species, which is similar to that of the natural glutathione peroxidase.

Expression and clinical significance of Ki-67, E-cadherin, and mesothelin in serous borderline ovarian tumor

OBJECTIVE

This study aimed to investigate the expression of Ki-67, epithelial cadherin (E-cadherin), mesothelin, and their correlations with clinicopathological features of serous borderline ovarian tumors (SBOTs).

MATERIALS AND METHODS

Immunohistochemistry was conducted to investigate the expression of a cellular proliferation-related factor (Ki-67) and metastasis-related factors (E-cadherin and mesothelin) in 41 cases of SBOTs, 30 benign ovarian tumor tissues, and 30 malignant ovarian tumor tissues.

RESULTS

The results showed that the expression rate of Ki-67 (46.3%) in SBOTs was higher than that in benign tumors (6.7%), but lower than that in ovarian carcinomas (80%). SBOTs significantly differed from benign ovarian tumors (p < 0.01) and carcinoma (p < 0.01). The positive expression rate of Ki-67 was significantly correlated with FIGO stage and peritoneal implantation of SBOTs (p < 0.01). The expression rate of E-cadherin was significantly lower in ovarian carcinomas (56.7%) than in SBOTs (80.5%) and benign ovarian tumors (90%; p < 0.05). The mesothelin expression in ovarian carcinomas and SBOTs significantly differed from that in benign ovarian tumors (p < 0.01). The positive expression rate of mesothelin was related to the serum CA125 level (p < 0.05). The expression of Ki-67 was positively correlated with the expression of E-cadherin and mesothelin in SBOTs.

CONCLUSION

SBOTs generally behave in a benign manner. Ki-67, E-cadherin, and mesothelin may play an important role in the oncogenesis and progression of SBOT. Patients with Ki-67 and mesothelin overexpression and low E-cadherin expression should be followed up.

Confocal laser endomicroscopy for superficial esophageal squamous cell carcinoma

BACKGROUND AND STUDY AIMS

Confocal laser endomicroscopy (CLE) allows subsurface imaging of gastrointestinal mucosa in vivo. The goal of the present study was to compare the endomicroscopic characteristics of cells and intrapapillary capillary loops (IPCLs) in normal and superficial esophageal squamous cell carcinoma (SESC).

PATIENTS AND METHODS

We recruited consecutive patients with SESC diagnosed by conventional endoscopy and confirmed by histopathology between July 2006 and May 2008. The confocal endoscopic images of these patients were collected and compared with the corresponding histology. The characteristic patterns of cells and IPCLs was then analyzed from these images of malignant and normal mucosa. The quality of images and interobserver variations of two endoscopists were also evaluated.

RESULTS

Overall, 64 samples from 57 subjects (27 SESCs, 30 controls) were examined by CLE. The confocal images corresponded to the hematoxylin and eosin staining from the same sites. The confocal images showed that there was a significantly higher proportion of squamous epithelial cells with irregular arrangement (79.4 % vs. 10.0 %, P < 0.001), increased diameter of IPCLs (26.0 microm vs. 19.2 microm, P < 0.001), and irregular shape IPCLs (82.4 % vs. 36.7 %, P = 0.0002) in the SESC group compared with the controls. Massive IPCLs with tortuous vessels (44.1 % vs. 0 %, P < 0.0001), and long branching IPCLs (23.5 % vs. 3.3 %, P = 0.0204) were frequently observed in the SESC group. In this study, about 35.5 % of images were graded as good quality, and the interobserver agreement for the prediction of cancerous mucosa was graded as substantial.

CONCLUSIONS

CLE can be used to distinguish cancerous from normal epithelium, which gives it potential value for early detection of esophageal carcinoma. The difficulty in obtaining good images in the esophagus by CLE is a latent problem.

[Rigid registration and fusion between SPECT and MRI/CT based on external fiducial alignment]

A convenient and effective method of rigid registration and fusion between SPECT and MRI/CT which is based on external fiducial alignment system is designed. After thresholding the image, many image processing arithmetics such as erosion, dilation are used to ensure the corresponding points which will be used to registrate. Then these points are used to minimize the cost function. In this way, an optimal rigid transform is gotten to registrate the images accurately and fuse them well. Error in the registration and fusion is reduced furthest by well designing the N-shape bracket which is used as the external fiducial alignment system and also by limiting the relative displacement between the bracket and the patient. Experimentation shows that this method can realize the registration and fusion of SPECT and MRI/CT effectively.

[Diagnosis and differential diagnosis of primary carcinoma of female peritoneum]

OBJECTIVE

Histogenesis and morphological features of 6 primary carcinomas of female peritoneum were studied.

METHODS

H&E staining, histochemical stainings and immunohistochemical stainings were used.

RESULTS

Among 6 primary carcinomas there were 4 cases of serous papillary carcinomas, 1 case of endometrioid carcinoma and 1 case of transitional cell carcinoma.

CONCLUSION

Primary carcinomas of the female peritoneum were histologically identical to that of the similar epithelial carcinomas arising from the ovaries. The diagnosis was made only when the ovaries are not involved and without no any evidence of similar epithelial carcinoma obtained in the ovaries, uterus or urinary organs. These tumors are considered arising from the secondary Mullerian system. D-PAS and CEA staining are helpful as the accessory criteria for the differential diagnosis between primary carcinoma of the peritoneum and malignant mesothelioma.