Aspheric intraocular lenses(IOLs)have been shown to provide better quality of vision than spherical IOLs.However,these lenses are not ideal for all patients.Surgeons may have different strategies for compensating for the patients's cornea spherical aberration,targeting a postoperative spherical aberration of zero or +0.10 ?m.But we must know that the negative spherical aberration aspheric IOLs require very good centration with respect to the visual axis of the eye.

The capsule endoscope swallowed from the mouth into the digestive system can capture the images of important gastrointestinal tract regions. It can compensate for the blind spot of traditional endoscopic techniques. It enables inspection of the digestive system without discomfort or need for sedation. However, currently available clinical capsule endoscope has some limitations such as the diagnostic information being not able to correspond to the orientation in the body, since the doctor is unable to control the capsule motion and orientation. To solve the problem, it is significant to track the position and orientation of the capsule in the human body. This study presents an AC excitation wireless tracking method in the capsule endoscope, and the sensor embedded in the capsule can measure the magnetic field generated by excitation coil. And then the position and orientation of the capsule can be obtained by solving a magnetic field inverse problem. Since the magnetic field decays with distance dramatically, the dynamic range of the received signal spans three orders of magnitude, we designed an adjustable alternating magnetic field generating device. The device can adjust the strength of the alternating magnetic field automatically through the feedback signal from the sensor. The prototype experiment showed that the adjustable magnetic field generating device was feasible. It could realize the automatic adjustment of the magnetic field strength successfully, and improve the tracking accuracy.
Capsule Endoscopes ; Endoscopy ; Gastrointestinal Tract ; Humans ; Magnetic Fields

Objective To develop a method for localizing a detecting capsule in the gastrointestinal tract.Methods A three-axis magnetic sensor was sealed in the detecting capsule.Three flat coils were fixed on patients' back.The coils were excited one by one to generate electromagnetic fields.The position and the orientation of the capsule could be determined by telemetering the signals from the magnetic sensor incorporated in the capsule.Results The telemetric localization system worked successfully.A localization model describing the relationship between the magnetic field strength and the position and orientation of the capsule,was correctly established basing on the principle of magnetic dipoles,and neural network algorithm was employed to solve a non-linear equation set.Conclusion The results showed that the localization method is feasible and the precision is higher than existing methods.The localization device can perform consecutive tracking and can be made into a portable type.After putting into practice,the device can also be used in food selection for astronauts by monitoring their gastrointestinal parameters in space.

Objective To study the regional cerebral glucose utilization with 18 F-fluorodeoxyglucose (FDG) PET and to investigate the correlation between cerebral glucose metabolism and the clinical characteristic of progressive supranuclear palsy (PSP).Methods A total of 13 patients with PSP and 30 matched healthy controls were performed 18F-FDG PET imaging at rest state.Visual inspection and statistical parametric mapping (SPM) were used to investigate regional cerebral metabolic rate of glucose (rCMRglc).Results Based on the visual inspection,PET imaging in the PSP patients showed that the focal hypometabolic areas mainly included the bilateral frontal cortex,midbrain and subcortical structures.Compared to the controls,voxel-based analysis showed that the regional glucose metabolism decreased in bilateral superior,middle frontal gyrus,cingulate gyrus,midbrain and subcortical structures including basal ganglion and thalamus,which were consisted with the clinical characteristics,such as vertical gaze palsy,pseudobulbar palsy,postural instability,axial rigidity,dementia and so on.Conclusion 18 F-FDG PET imaging is helpful for the early diagnosis of PSP.

Objective To evaluate the safety and feasibility of Wingspan stent for patients with symptomatic M1 stenosis of middle cerebral artery (MCA). Methods Thirty-two cases with recurrent symptomatic MCA stenosis resistant to medical therapy treated by self-expanding stent were reviewed retrospectively [average (49±19) years old, 13 women]. All patients underwent angioplasty and stenting with the Gateway balloon-Wingspan stent system. After 6 months, all patients were followed up by telephone or clinic, and advised followed up with DSA or TCD. Results Thirty-two patients were successfully stented during the first treatment session. The mean degree of stenosis reduced from (76.5±15.4)% to (19.3±9.2)%. The number of complicating subarachnoid hemorrhage was one, and occlusion occurred on one patients related to balloon angioplasty. During a follow-up of 6 months, there was no recurrence of transient ischemic attack or stroke in 32 available patients. Cerebral hemodynamics using transcranial Doppler monitoring were normal in 19 follow-up patients. Six-month angiographic follow-up was obtained in 5 patients, demonstrating good patency in 5 stenting vessels. The other patients refused to perform TCD or DSA. Conclusions Wingspan stent for symptomatic stenosis of middle cerebral artery appears to be a safe and feasible under strict control of periperformeral project. However further study is needed to evaluate the long-term effect.

Objective To investigate the correlation between R219K (rs2230806 G/A) polymorphism in the ATP binding cassette transporter (ABC) A1 gene and ischemic stroke in a Chinese Han population. Methods A total of 360 patients with ischemic stroke and 358 healthy subjects were selected using a case-control study design. The patients with ischemic stroke were redivided into either a large artery atherosclerosis (LAA) group or a smal artery occlusion (SAO) group according to the TOAST criteria. Polymerase chain reaction-restriction fragment length polymorphism analysis and direct sequencing method were used to detect R219K (rs2230806 G/A) polymorphism in the ABCA1 gene. Results Using GG genotype as a reference, the AA genotype reduced the risk of ischemic stroke by 65% (odds ratio [OR] 0. 35, 95%confidence interval [CI] 0. 23 - 0. 55; P < 0. 001) and the onset risk of LAA by 77% (OR 0. 23, 95% CI 0. 13 - 0. 40; P < 0. 001), but it did not have significant correlation with SAO. The interaction of rs2230806 G/A polymorphisms with smoking, drinking, hypertension, and diabetes had no significant effect on the on-set risk of ischemic stroke (al P > 0. 05). AA genotype was enable to increase the high-density lipoprotein cholesterol levels of the patient group (OR 0. 35, 95% CI 0. 28 - 0. 42; P < 0. 001) and the control group (OR 0. 19, 95% CI 0. 14 - 0. 23; P < 0. 001) significantly, while it did not have significant correlation with the low-density lipoprotein cholesterol, total cholesterol, and triglyceride. Conclusions R219K (rs2230806 G/A) polymorphism in the ABCA1 gene may be associated with the reduced predisposition of ischemic stroke in a Chinese Han population, especialy LAA. The A alele may be a hereditary protective factor; its mechanism may be associated with the increase of high-density lipoprotein cholesterol levels.

Objective To investigate the effect of partial sleep deprivation (PSD) on cardiac electric activity and function of vascular endothelium. Methods Eighteen Sprague-Dawley rats were randomly divided into two groups (9 each):PSD group and control group. PSD lasted 10 days,20 hours each day. Body weight and surface electrocardiogram (S-ECG) were examined and recorded 1d before PSD,and 1d,4d,7d and 10d after PSD. Serum concentrations of glucose,total cholesterol (TC),triglyceride (TG),high-density lipoprotein cholesterol (HDL-C),low-density lipoprotein cholesterol (LDL-C),creatin kinase (CK),creatin kinase-MB (CK-MB),high-sensitivity C-reactive protein (hs-CRP),nitric oxide (NO),von Willebrand factor (vWf),endothelin-1 (ET-1) and E-selectin were determined the next day after 10d of PSD. Results Compared to that 1d before PSD,body weight in PSD groups decreased significantly,while increased obviously in control group. Compared to that in control group,the body weight of rats decreased significantly (P

Objective To intelligently adjust the driving force of a remote-controlled drug delivery capsule based on the postural information in intestines,so as to achieve the control of speed and dosage of drug delivery and reduce the energy consuming.Methods A six-axis sensor MPU6050 was used,and its Z axis was coincident with the central axis of the drug delivery capsule so as to made the medicine discharge port pointing to the Z direction.The angular velocities and accelerations of X,Y,Z axes were monitored,transformed to quaternion with built-in digital motion processor,and then converted to Euler angle form.The intelligence adjustment of driving force could be achieved by accessing the real-time attitude angle of the capsule.Results The results of experiments showed that the error between the actual and the attitude angle measured by the sensor was less 1°.Conclusions The intelligent adjustment scheme of driving force of a gastrointestinal remote-controlled drug delivery capsule was designed.The real-time attitude angles of the capsule could be obtained with high spped and precision.This study can provide the theoretical and experimental basis for the intelligent adjustment of the driving force.

Objective To investigate the correlation between methylenetetrahydrofolate reductase (MTHFR) gene 3 '-untranslated region rs4846049 G/T polymorphism and risk of ischemic stroke in a Chinese Han population. Methods A total of 396 patients with ischemic stroke and 378 healthy subjects (control group ) were selected using a case-control study design. Large artery atherosclerosis and small artery occlusion in the case group were 268 and 128 cases, respectively. Polymerase chain reaction-restriction fragment length polymorphism and the direct sequencing method were used to detect MTHFR gene rs4846049 G/T polymorphism. Results As compared to the GG genotype, the TT genotype significantly increased the risk of ischemic stroke (odds ratio [OR] 2. 87, 95% confidence interval [CI] 1. 43-5. 76;P=0. 003). Compared with G allele, T allele significantly increased the risk of the disease (OR 1. 62, 95% OR 1. 28-2. 06; P< 0. 001 ). Subgroup analyses showed that the rs4846049 G/T polymorphism could significantly increase the onset risks of LAA and SAO subtype stroke (all P<0.05). Conclusions MTHFR gene rs4846049 G/T polymorphism may be associated with the increased susceptibility to ischemic stroke in the Chinese Han population. The T allele may be a genetic risk factor for ischemic stroke in the Chinese Han population.

Objective To compare the botanical characters, yield, and active components in flowers of seven various cultivars from Chrysanthemum morifolium in planting base in Sheyang County, Northern Jiangsu Province and provide the theoretical and practical basis for plangting and expanding reproduction of improved cultivars of C. morifolium. Methods Based on the field experiment, comparison, and analysis of the botanical characters, yield, and active components (total flavonoid and chlorogenic acid) in flowers of the seven cultivars from C. morifolium, such as “Hongxinbaiju”, “Changbanbaiju”, and “Hubaiju” etc. Results The botanical characters of flowers are vary different among the seven cultivars from medicinal C. morifolium in the planting base; the amount of single capitulum is the main factor influencing on the yield of C. morifolium, the yield of “Hongxinbaiju” is the highest; the contents of total flavonoid and chlorogenic acid of “Changbanbaiju” are the highest in the seven cultivars. Conclusion From all the aspects, in the planting base of Northern Jiangsu Province, “Hongxinbaiju” and “Changbanbaiju” can be extended as major cultivars with good characters of superior quality and high yield, “Hubaiju” and “Huangjuhua” also can be cultivated at present.