Towards Semi-Autonomous Colon Screening Using an Electromagnetically Actuated Soft-Tethered Colonoscope Based on Visual Servo Control.

OBJECTIVE: Conventional colonoscopy using a flexible colonoscope remains two major limitations, including patient discomfort and difficult manipulations for surgeons. Robotic colonoscopes have been developed to conduct colonoscopy in a patient-friendly manner. However, most robotic colonoscopes still maintain nonintuitive and difficult manipulations, which limits their clinical applications. In this paper, we demonstrated visual servo-based semi-autonomous manipulations of an electromagnetic actuated soft-tethered (EAST) colonoscope, which aims to lower difficulties of robotic colonoscope manipulations. METHODS: Kinematic modeling of EAST colonoscope is conducted, with an adaptive visual servo controller established. Template matching method and a lumen and polyp detection model are developed to enable semi-autonomous manipulations, including region-of-interest automatic tracking and autonomous navigation with automatic polyp detection. RESULTS: The EAST colonoscope demonstrates visual servoing with an average convergence time of around 2.5 s and performs disturbance rejection within 3.0 s. Semi-autonomous manipulations were conducted in both a commercialized colonoscopy simulator and an ex-vivo porcine colon to show the efficacy of reducing the user workload compared to manual control. CONCLUSION: The EAST colonoscope can perform visual servoing and semi-autonomous manipulations with the developed methods in both laboratory and ex-vivo environments. SIGNIFICANCE: The proposed solutions and techniques improve the autonomy level of robotic colonoscopes and reduce user workloads, which promotes the development and clinical translation of robotic colonoscopy.

[Masquelet technique combined with artificial dermis for the treatment of bone and soft tissue defects in rabbits].

OBJECTIVE: To investigate the effect of Masquelet technique combined with artificial dermis on repairing bone and soft tissue defects in rabbits, and to observe the microstructure and vascularization of induced membrane, so as to guide the clinical treatment of Gustilo-Anderson type Ⅲ open fracture with large bone defect and soft tissue defect. METHODS: Eighty male rabbits, weighing 2.03-2.27 kg (mean, 2.11 kg), were selected. The bilateral thighs of 64 rabbits were randomly divided into experimental group and control group, the remaining 16 rabbits were sham operation group. Bone and soft tissue defect models of femur were made in all rabbits. In the experimental group, the first stage of Masquelet technique was used [polymethyl methacrylate bone cement was filled in bone defect area] combined with artificial dermis treatment; in the control group, the first stage of Masquelet technique was used only; in the sham operation group, the wound was sutured directly without any treatment. Four rabbits in sham operation group and 16 rabbits in the experimental group and control group were sacrificed at 2, 4, 6, and 8 weeks after operation, respectively. The induced membranes and conjunctive membranes were observed on both sides of the femur. The membrane structure was observed by HE staining, and the microvessel density (MVD) was counted by CD34 immunohistochemical staining. RESULTS: Gross observation showed that the spongy layer of collagen in the artificial dermis of the experimental group disappeared completely at 4 weeks after operation, and the induced membrane structure of the experimental group and the control group was complete; the membrane structure of the control group was translucent, and the membrane structure of the experimental group was thicker, light red opaque, accompanied by small vessel proliferation. The membrane structure of the experimental group and the control group increased gradually from 6 to 8 weeks after operation. In the sham operation group, only scar tissue proliferation was observed over time. HE staining showed that a large number of muscle fibers and a small amount of collagen fibers proliferation with inflammatory cell infiltration could be seen in the experimental group and the control group at 2 weeks after operation; most of the sham operation group were muscle fibers with a small amount of interfibrous vessels. At 4 weeks after operation, collagen fibers increased and some blood vessels formed in the experimental group. The nuclei of collagen fibers in the control group were round-like, while those in the experimental group were flat-round. At 6 and 8 weeks after operation, the collagen fibers in the experimental group and the control group increased. The nuclei of the collagen fibers in the control group were still round-like. The nuclei of the collagen fibers in the experimental group were fusiformis and deeply stained compared with those in the control group. The proliferation of blood vessels was observed in both groups, and the number of proliferation vessels in the experimental group was increased compared with that in the control group. In the sham operation group, a large number of fibroblasts still appeared, but no significant proliferation of blood vessels with time was observed. CD34 immunohistochemical staining showed that MVD in each group increased gradually with the prolongation of time after operation. MVD in the sham operation group was significantly higher than that in the experimental group and the control group at 2 weeks after operation, and significantly smaller than that in the experimental group and the control group at 4, 6, and 8 weeks after operation ( P<0.05). MVD in the experimental group was significantly higher than that in the control group at 4 and 6 weeks after operation ( P<0.05), but there was no significant difference in MVD between the two groups at 2 and 8 weeks ( P>0.05). CONCLUSION: Masquelet technique combined with artificial dermis in the treatment of femoral bone defect and soft tissue defect in rabbits can significantly promote the vascularization of membrane structure at 4-6 weeks after operation. The combination of these two methods has guiding significance for the treatment of Gustilo-Anderson type Ⅲ open fracture with bone and soft tissue defects.

[Effect of Heshouwuyin on the expression of Cox7a2 protein in testis tissue of exercised-induced fatigue rat].

OBJECTIVE: To explore the effect of Heshouwuyin on the expression of cytochrome C oxidase7a2 (Cox7a2) in testis tissue of rats with exercised-induced fatigue. METHODS: Fifty SD rats were divided into normal control group (A group), Heshouwuyin administered normal group (B group), model control group (C group), Heshouwuyin treated group (D group) and Heshouwuyin prevented group (E group) randomly with 10 rats for each. The exercise-induced fatigue models in rats of C, D, E groups were established. The rats in D group were treated with Heshouwuyin [20 g/(kg x d), contained crude drug 9.6 g/mL] for 60 days (during the 42 days of modeling and after the 18 days of modeling). The rats in E group were also treated with Heshouwuyin for 60 days (but before the 18 days of modeling and during the 42 days of modeling). Beckmancoulter Unicel Dxl 800 was used to detect the level of serum testosterone, according to the manufacture's instructions. Western blot and RT-PCR were used to observe the differential expression of Cox7a2. RESULTS: The level of serum testosterone in C group was decreased compared with A group (P < 0.05), which implied the success of modeling. Compared with group A, the level of serum testosterone in B, D, E groups were increased (P < 0.05). Cox7a2 protein was expressed mainly in leydig cell and spermatocyte. Compared with A,B, D, E groups, the expression of Cox7a2 protein and mRNA in C group increased (P < 0.05), and there no significant difference was observed between group A and B, as well as group D and E. CONCLUSION: The expression of Cox7a2 was down-regulated by Heshouwuyin.

Effects of moderate exercise over different phases on age-related physiological dysfunction in testes of SAMP8 mice.

Oxidative stress and chronic inflammation have been implicated in the testicular aging process. Different types and moderate-intensity of regular exercise may reduce age-related physiological dysfunction associated with inflammation and oxidative stress, but such effects of moderate-intensity of exercise over different phases of life in testes have not been reported. In this study, male SAMP8 mice, a senescence-accelerated strain, were maintained as sedentary (sed) or subjected to daily 15-min periods of swimming exercise between ages of 2-7 months (lifelong), 2-4 months (earlier) or 5-7 months (late). Age-related changes, including serum testosterone levels and biomarkers of inflammation and oxidative stress were analyzed at the end of the experiment. All exercise groups showed significantly greater serum testosterone levels and decreased age-related inflammation and oxidative stress compared with the sedentary group. Exercise also increased expression and activity of the nuclear factor erythroid 2-related factor (Nrf2), a transcriptional regulator of the cellular anti-oxidant system, and decreased expression and activity of nuclear factor kappa beta (NF-κB), a mediator of inflammatory molecules, in the nucleus of testicular cells. However, lifelong and earlier groups generally showed significantly better protective effects than the late group against age-related physiological dysfunction in testes. Thus, lifelong exercise and earlier phase exercise were most effective in counteracting oxidative stress and inflammation and in preserving testes function through regulation of Nrf2 and NF-κB. These results advocate the benefits of lifelong exercise and emphasize a greater protection against male aging by instituting exercise earlier rather than late in life.

New fluorescent probes based on supramolecular diastereomers for the detection of 2-nitrophenol.

A couple of new fluorescent probes, based on diethoxycarbonyl glycoluril, were synthesized and characterized by (1)H NMR, X-ray crystal structure. The probes were found to be relatively highly fluorescence with quantum yields of 0.20 and 0.18, respectively, at room temperature in THF solution. Both of the proposed probes were tested using different phenolic compounds, showing very high selectivity and sensitivity for 2-nitrophenol by forming a 1:1 complex in THF-MeOH (9:1, v/v). Additionally, the sensors could be used for the qualitative analysis of 2-nitrophenol in real water samples.

Diethyl 2-tert-butyl-4,11-dioxo-2,3-di-hydro-cis-1H,5H,10H-2,3a,4a,10a,11a-penta-azabenzo[f]indeno[2,1,7-ija]azulene-11b,11c-dicarboxyl-ate.

In the title mol-ecule, C(24)H(31)N(5)O(6), the two ethyl fragments are each disordered over two conformations [occupancy ratios 0.58 (13)/0.42 (13) and 0.56 (12)/0.44 (12)]. The crystal packing exhibits inter-molecular non-classical C-H⋯O hydrogen bonds and π-π inter-actions between benzene rings [centroid-centroid distances = 3.836 (5) Å].

Diethyl 6,9,17,20-tetra-bromo-2,13-di-oxo-hexa-cyclo-[10.10.2.0.0.0.0]tetra-cosa-5,7,9,16,18,20-hexa-ene-23,24-dicarboxyl-ate.

In the title mol-ecule, C(26)H(22)Br(4)N(4)O(6), the dihedral angle between the aromatic rings is 30.0 (1)°. One ethyl fragment is disordered between two positions in a 1:1 ratio. The crystal packing exhibits weak inter-molecular C-H⋯O hydrogen bonds and short Br⋯O contacts of 3.349 (6) Å.

2,6-Bis(2-chloro-ethyl)-8b,8c-diphenyl-perhydro-2,3a,4a,6,7a,8a-hexa-azacyclo-penta-[def]fluorene-4,8-dithione.

In the title mol-ecule, C(24)H(26)Cl(2)N(6)S(2), the two phenyl rings form a dihedral angle of 51.95 (7)° and the distance between their centroids is 4.156 (8) Å. The crystal packing exhibits weak inter-molecular C-H⋯S and C-H⋯N hydrogen bonds.

N-Phenyl-N-(3-phenyl-prop-2-yn-yl)aniline.

In the title compound, C(21)H(17)N, synthesized by a three-component coupling reaction in the presence of copper(I) iodide, the N-bound phenyl rings form a dihedral angle of 72.5 (1)° with each other. Thereare no remarkable inter-actions in the crystal structure.