BACKGROUND: Fibrous scaffolds prepared by electrospinning possess similar structure to extracellular matrix, and exhibit convenience in introducing bioactive ceramics into polymer matrices, which have distinct superiority in making bone tissue scaffolds materials.OBJECTIVE: To evaluate the bioactivity of gas-jet/electrospun nanosized hydroxyapatite (nHAP)/poly (3-hydroxybutyrate) (PHB) scaffolds for being used as bone tissue engineering scaffolds.DESIGN, TIME AND SETTING: The in vitro cytology experiment was performed at the State Key Laboratoty of Oral Diseases,Sichuan University between March 2008 and April 2009.MATERIALS: The gas-jet/electrospun PHB and 10% nHAP/PHB scaffolds were prepared.METHODS: Rats bone marrow-derived mescenchymal stem cells were incubated on the nHAP/PHB scaffolds were served as experimental group, incubated on the PHB scaffolds were as control group, and cells incubated on cell culture plate were consided to be blank control group.MAIN OUTCOME MEASURES: mRNA transcript expression of bone-related markers, including alkaline phosphatase, type I collagen, and osteocalcin, were quantified utilizing reverse transcription-polymerase chain reaction (RT-PCR) at day 14 after culture.RESULTS: After 14 days, the bone-related markers were expressed in three groups, and had higher transcript levels in the cells cultured on the nHAP/PHB scaffolds than those on the PHB scaffolds and cell culture plate.CONCLUSION: The gas-jet/electrospun nHAP/PHB scaffolds present good bioactivity in vitro and have the potential to be used in bone tissue engineering.

BACKGROUND:Poly(3-hydroxybutyrate) is approved as its excel ent biocompatibility, biodegradability and piezoelectric properties, but there are also some deficiencies, such as high breakability and poor hydrophilicity. METHODS:Poly(3-hydroxybutyrate) was mixed with different mass percentages of nanohydroxyapatite (0, 10%, 20%and 30%) to prepare new composite fibrous scaffolds through electrospinning process. The microstructure, group composition, crystal ine phase distribution, thermal properties and surface wettability of the scaffolds were detected. RESULTS AND CONCLUSION:Under the scanning electron microscope, with the increase of nano-hydroxyapatite content, more and more nano-hydroxyapatite particles were distributed evenly on the composite fiber surface;the fiber surface was basical y covered with nano-hydroxyapatite particles at the content of 30%, and the roughness of the fiber surface also increased. Results from differential scanning calorimetry and X-ray diffraction showed that the nano-hydroxyapatite reduced the crystal inity of poly(3-hydroxybutyrate) and the crystal tacticity, and this phenomenon became more evident with the increase of nano-hydroxyapatite content. Additional y, the higher the content of nano-hydroxyapatite content, the lower the contact angle and the higher the hydrophily. These findings indicate that the nano-hydroxyapatite/poly(3-hydroxybutyrate) ultrafine-fibrous scaffold using electrospinning technology can effectively improve the surface wettability and crystal inity of the material as wel as the material hydrophily and brittleness, and the higher the content of nano-hydroxyapatite, the more obvious the effect.

Objective To investigate the value of MSCTA in diagnosing the origin of abdominal ectopic ovarian tumor. Methods Twenty-eight patients with 30 ectopic ovarian tumors that mainly manifested as abdominal lumps were evaluated with MSCTA retrospectively. Vascular three-dimensional reconstruction by VR based on add vessel (AV) and MIP was performed for all these patients after MSCT scanning.The origin of these tumors was judged by the feeding artery and ovarian vascular pedicle (OVP) sign.The result was compared with surgical findings.Results The maximum diameter of the 30 ectopic ovarian tumors ranged from 5.2 to 19.5 cm with an average of 9.3 cm.Of the 30 ectopic ovarian tumors, the ramus ovaricus arteriae uterinae (ROAU) and ovarian artery (OA) were demonstrated in 96.7% (29/30) and 56.7% (17/30) respectively.The feeding artery of the tumor was ROAU (29 cases) or OA (1 case), and OA participated in feeding the tumor in 16 cases.The accuracy rate of diagnosis of ectopic ovarian tumors according to the feeding artery was 100% (30/30).According to OVP the accuracy rate was 85.2% (23/27) with an incidence of 76.7% (23/30).Conclusion By showing ROAU and OA as the feeding artery and ovarian vein (OV) as the draining vein, MSCTA can accurately diagnose ectopic ovary tumors in the abdomen.

OBJECTIVEThe aim of this study was to investigate the korrosionsneigung of three metal specimens for casing removable denture by means of electrochemical method.

METHODSThree kinds of test specimens were prepared, including cobalt-chromium alloy, nickel-chrome alloy with titanium and pure titanium. Then they were analyzed via linear polarization in artificial saliva simulating oral environment. From this electrochemical test the polarization curves of these kinds of specimens were recorded. Then the scanning electron microscope (SEM) and X-ray diffractometer (XRD) were applied to assess the morphology and phase changes before and after electrochemical corrosion.

RESULTSNo typical Tafel curve had been recorded for pure titanium, other than cobalt-chromium alloy and nickel-chrome alloy with titanium. Nickel-chrome alloy with titanium got more negative corrosion potential and higher corrosion current than cobalt-chromium alloy. Via SEM, the obvious changes were observed on the morphology and phase before and after corrosion on cobalt-chromium and nickel-chrome alloy with titanium specimens while pure titanium having no change. The XRD provided us little changes on these all three materials.

CONCLUSIONThe results confirm that the korrosionsneigung of the studied cobalt-chromium alloy in artificial saliva is lower than that nickel-chrome alloy with titanium. Pure titanium is the most stable one of the three materials and is extreme hard to be etched.

Chromium ; Chromium Alloys ; Corrosion ; Dental Alloys ; Electrochemistry ; Nickel ; Titanium

OBJECTIVEIn order to compare the influence of casting and laser welding on magnetic retentive force, the magnetic retentive forces of laser-melted and cast post-keepers of the magnetic attachments were measured in vitro.

METHODS5 cast and 6 laser-melted post-keeper specimens (Magfit MD800) were formed, respectively. Using untreated keeper as control group, the vertical magnetic retentive forces were measured by a universal testing machine.

RESULTSThe average vertical magnetic retentive force of the laser-melted post-keeper group and the cast post-keeper group in vitro were (4.223 +/- 0.217,0)N, (3.792,9 +/- 0.296,4)N, respectively. Compared with the cast post-keeper group, the average vertical magnetic retentive force of the laser-melted post-keeper groups was much higher in vitro (P < 0.05).

CONCLUSIONLaser welding had less influence on the magnetic retentive force of the magnetic attachments than casting.

Dental Alloys ; Dental Casting Investment ; Dental Casting Technique ; Dental Prosthesis Retention ; instrumentation ; Dental Soldering ; methods ; Denture Precision Attachment ; Electromagnetic Fields ; Lasers ; Magnetics ; instrumentation ; Post and Core Technique ; Stainless Steel ; Welding ; methods

The thyroid function test is universally used for the evaluation of thyroid function. However, there are factors other than endocrine diseases, such as special physiological conditions, interference in laboratory measurement, or disorders in other systems that should be taken into consideration. When encountering thyroid function test results that are not in line with clinical manifestation, a comprehensive evaluation is essential for a correct and timely diagnosis. We presented a case of a significant rise in serum total triiodothyronine(TT 3) secondary to multiple myeloma. Through case studies and literature review, we intended to provide clinicians with experience for better interpretation of abnormal thyroid function test results.