High-precision laser beam lateral displacement measurement based on differential wavefront sensing.

Accurately lateral displacement measurement is essential for a vast of non-contact sensing technologies. Here, we introduce a high-precision lateral displacement measurement method based on differential wavefront sensing (DWS). Compared to the conventional differential power sensing (DPS) method, the DWS method based on phase readout has the potential to achieve a higher resolution. The beam lateral displacement can be obtained by the curvature distribution of the wavefront on the surface of the detector. According to the theoretical model of the DWS method, the sensitivity of the lateral displacement can be greatly improved by increasing the wavefront curvature of the measured laser beam by means of lenses. An optical system for measuring the lateral displacement of the laser beam is built and calibrated by a high-precision hexapod. The experimental results show that the DWS-based lateral displacement measurement achieves a resolution of 40 pm/Hz1/2 (at 1-10 Hz) with a linear range of about 40 µm, which is consistent with the theoretical model. This technique can be applied to high-precision multi-degree-of-freedom interferometers.

[Design space approach to optimize first ethanol precipitation process of Dangshen].

Design space approach is applied in this study to enhance the robustness of first ethanol precipitation process of Codonopsis Radix (Dangshen) by optimizing parameters. Total flavonoid recovery, dry matter removal, and pigment removal were defined as the process critical quality attributes (CQAs). Plackett-Burman designed experiments were carried out to find the critical process parameters (CPPs). Dry matter content of concentrated extract (DMCE), mass ratio of ethanol to concentrated extract (E/C ratio) and concentration of ethanol (CEA) were identified as the CPPs. Box-Behnken designed experiments were performed to establish the quantitative models between CPPs and CQAs. Probability based design space was obtained and verified using Monte-Carlo simulation method. According to the verification results, the robustness of first ethanol precipitation process of Dangshen can be guaranteed by operating within the design space parameters. Recommended normal operation space are as follows: dry matter content of concentrated extract of 45.0% - 48.0%, E/C ratio of 2.48-2.80 g x g(-1), and the concentration of ethanol of 92.0% - 92.7%.

Two new flavonoid glycosides from Semen Ziziphi Spinosae.

Two novel flavonoid glycosides, 6"'-dihydrophaseoylspinosin (1) and 6″,6"'-diferuloylspinosin (2), were isolated from the MeOH extract of Semen Ziziphi Spinosae, together with six known flavonoids, isovitexin-2″-O-ß-(6-O-E-feruloyl)glucopyranoside (3), spinosin (4), isospinosin (5), 6"'-feruloylspinosin (6), swertisin (7), and isovitexin-2″-O-ß-d-glucopyranoside (8). The structures of 1 and 2 were elucidated by spectroscopic methods including UV, IR, ESI-TOF-MS, 1D NMR, and 2D NMR experiments.

A novel spinosin derivative from Semen Ziziphi Spinosae.

A novel spinosin derivative, 6‴-(4‴'-O-ß-D-glucopyranosyl)-vanilloyl spinosin (1) was isolated from the methanol extract of Semen Ziziphi Spinosae, together with five known flavonoids, swertish, spinosin, 6‴-feruloylspinosin, isospinosin and kaempferol 3-O-α-L-rhamnopyranosyl-(1 → 2)-O-[O-α-L-rhamnopyranosyl-(1 → 6)]-ß-D-glucopyranoside, and two alkanoids, zizyphusine and 6-(2',3'-dihydroxyl-4'-hydroxymethyl-tetrahydro-furan-1'-yl)-cyclopentene[c]pyrrole-1,3-diol. The structure of compound 1 was elucidated by spectroscopic methods including UV, IR, ESI-TOF-MS, 1D, and 2D NMR techniques.

Tetraethylammonium enhances the rectal and colonic motility in rats and human in vitro.

Hirschsprung's disease is the congenital absence of generating the peristaltic contractions transmitting from the proximal colon to rectum. We previously have found that tetraethylammonium (TEA), the nonselective Ca(2+)-activated K(+) channel blocker, increases the maximal contractile force and the amplitude of the contraction in rat duodenum. The present study is to test the effect of TEA on motility of colon and rectum from rats and Hirschsprung's disease patients in vitro, in order to find an alternative method to improve the syndrome of Hirschsprung's disease. The rectal and colonic motility was recorded by a tension transducer connected to a biology function experiment system. Histology was analyzed with standard hematoxylin and eosin staining. TEA (1, 3, and 5 mM) significantly increased the amplitude and frequency of contractility of colon and rectum from rats in longitudinal and circular direction. TEA at 5 and 15 mM concentrations showed no effect on histology of colon and rectum from rats that were administered locally with TEA into colon lumen from anus for 10 days. TEA at 15 mM increased the amplitude and frequency of contractions of the colon and rectum from Hirschsprung's disease patients. Our data showed that TEA increased the contractility of colon and rectum from rats and Hirschsprung's disease patients in vitro, suggesting that local administration of TEA in colon or rectum lumen might be an alternative method to ameliorate the syndrome of Hirschsprung's disease patients who are not cured completely by surgery or not suitable for surgery.

A new modification of transanal Swenson pull-through procedure for Hirschsprung's disease.

BACKGROUND: The one-stage pull-through procedures for Hirschsprung's disease (HD) have become popular because it is well accepted by surgeons and mothers with no visible scar and a short hospital stay. It represents the latest development in the concept of a minimally invasive surgery for HD. We introduce a new method of transanal one-stage pull-through for Hirschsprung's disease, different from the transanal Soave procedure. METHODS: One hundred and thirty-four patients aged 9 days to 5 years underwent a transanal one-stage pull-through procedure. The diagnosis was definite by barium enema or rectal biopsies preoperatively. The patients were anesthetized and placed in the lithotomy position. A urinary catheter was optional. Giving anorectal dilatations for half a minute, a pull-through of the rectum above the peritoneal reflection and into the intussusception was performed. Fine silk suturing was performed circumferentially at the level of that point which was used for traction for the distal end. Another circumferential suture was performed parallel 0.5 cm distance above the original one and used for traction for the proximal intestines. The full-thickness rectal wall was truncated between the above two circumferential sutures with cautery. The proximal intestines were pulled down and the mesenteric vessels were dissected with ligation until normal intestines were accessed; the presence of ganglion cells was determined by intraoperative rapid frozen section. The distal end was dissected anteriorly 2.5- 3.5 cm above the dentate line. The posterior rectal wall was split longitudinally and dissected to a point 0.5- 1.0 cm above the dentate line. The segment of the lesion was resected. The length of bowel resected ranged from 12 to 50 cm (median 16.5 cm). An oblique anastomosis was made. RESULTS: The mean operating time was 70 minutes. Postoperative rectal dilation was not required. The patient tolerated feeding on the first postoperative day. Eighty-eight patients were followed-up. All these patients had 2- 3 bowel movements per day at postoperative month 1. They were discharged within 4.5 days after the operation. Six patients presented with complications. All recovered by reoperation or conservative treatments. CONCLUSION: The modification of the transanal Swenson pull-through procedure for Hirschsprung's Disease is an easy adaptation to a well-established technique and has a reasonable result.