Isolation of a 1,2-dialuminacyclobutene.
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Journal Article↗
Biomedical subjects
Xiaoqing Zhu
Publications and source records attributed to Xiaoqing Zhu.
Light field compression using disparity-compensated lifting and shape adaptation.
We propose disparity-compensated lifting for wavelet compression of light fields. With this approach, we obtain the benefits of wavelet coding, such as scalability in all dimensions, as well as superior compression performance. Additionally, the proposed approach solves the irreversibility limitations of previous light field wavelet coding approaches, using the lifting structure. Our scheme incorporates disparity compensation into the lifting structure for the transform across the views in the light field data set. Another transform is performed to exploit the coherence among neighboring pixels, followed by a modified SPIHT coder and rate-distortion optimized bitstream assembly. A view-sequencing algorithm is developed to organize the views for encoding. For light fields of an object, we propose to use shape adaptation to improve the compression efficiency and visual quality of the images. The necessary shape information is efficiently coded based on prediction from the existing geometry model. Experimental results show that the proposed scheme exhibits superior compression performance over existing light field compression techniques.
Algorithms↗
[Local resection of ciliary body tumors with vitreoretinal surgery].
OBJECTIVE: To investigate the effects, safety and indication of local resection of ciliary body tumors with vitreoretinal surgery. METHODS: Twelve patients with ciliary body tumors, including 5 males and 7 females with the age range 13 - 48 years (average 32 years) were treated with local resection. Ultrasound biomicroscopy (UBM) and ultrasonography confirmed the tumors, and the surgery was performed under hypotensive general anesthesia or local anesthesia. The range of the diameters of tumors was 5 - 20 mm and of the thickness was 4 - 12 mm. Retinal detachment was detected in 2 eyes. Local lamellar sclerocyclectomy or sclerocyclochoroidectomy with vitreoretinal surgery was performed for the resection. The surgery included lensectomy and vitrectomy using perfluorocarbon liquid, endolaser and gases or silicone oil tamponade and also scleral allograft if necessary. The resected tumors were diagnosed by pathologic examinations. RESULTS: There were no tumor recurrence and metastasis during follow-up 7 - 38 months (average 14.2 months). In the last follow-up date, the visual acuities were less than 0.05 in 1 case, 0.05 - 0.2 in 3 cases and 0.3 - 1.0 in 8 cases. The pathologic diagnoses included malignant melanoma in 5 cases, melanocytoma in 2 cases, adenoma of non-pigmented ciliary epithelium in 3 cases, neurofibroma in 1 case and glioma in 1 case. CONCLUSION: Local resection of ciliary tumor not only can conserve the eyeball, but also part of vision, and the accurate diagnosis can also be made from the resected tissues. With vitreoretinal surgery, it can avoid complications and improve the success rate. It is a safe and effective method for benign or malignant tumors of the ciliary body.
Adolescent↗
Energetics of Multistep versus One-step Hydride Transfer Reactions of Reduced Nicotinamide Adenine Dinucleotide (NADH) Models with Organic Cations and p-Quinones.
Free energy changes of each elementary step involved in the formal hydride transfer (H(-)(T)) reactions (including the so-called "one-step" H(-)(T) and "multistep" H(-)(T) mechanisms) of the reduced nicotinamide adenine dinucleotide (NADH) models with various cations and quinones (17) were investigated either by direct thermodynamic measurements or by calculations from thermochemical cycles. Based on the energetic data thus derived, combined with kinetic observations (particularly kinetic isotope effects), the mechanistic characteristics of the NADH-mediated reductions were systematically analyzed. Practical guidelines that resulted from these analyses suggest that a mutistep mechanism (e(-)-H(*) or e(-)-H(+)-e(-)) would be followed if the energy gap of the initial electron transfer [DeltaG(e(-)(T))] between the NADH model compound and the reducing substrate is considerably smaller than the empirical critical limit of 1.0 V for an endothermic e(-)(T). In contrast, if DeltaG(e(-)(T)) is much greater than 1.0 V, a concerted one-step H(-)(T) may take place. The guideline also suggests that a "hybrid" mechanism is possible if the DeltaG(e(-)(T)) is in an intermdiate situation.
Journal Article↗