基于分形和小波的混合图像压缩

从近年来受人瞩目的分形和小波图像压缩方法出发,分析了两种图像压缩方法的特点及利弊。运用小波域及DCT域下的分形压缩图像方法,提高了编码速度,得到较高的压缩比和信噪比,但重构图像质量还存在块状效应。为此,提出了几种方法结合起来的综合方法,进一步提高图像的质量,在压缩比和信噪比之间取得良好的折衷。     

Evidence for a ‘preinvasive’ variant of fungal sinusitis: Tissue invasion without angioinvasion

Clinical experience has suggested the existence of an intermediate form of fungal sinusitis between the categories of non-invasive fungal sinusitis (non-IFS) and invasive fungal sinusitis (IFS). This fungal sinusitis variant demonstrates unhealthy mucosa by endoscopy with fungal invasion, but lacks angioinvasion microscopically, representing what clinically behaves as a ‘pre-invasive’ subtype of fungal sinusitis. Unlike non-IFS disease, patients with pre-invasive fungal sinusitis were still felt to require anti-fungal medications due to histologic presence of invasive fungus. While sharing some clinical features of IFS, these ‘intermediate’ patients were successfully spared extended and repeated surgical debridements given the microscopic findings, and have been successfully treated with shorter courses of antifungal therapy. These select patients have had favorable outcomes when managed in a judicious and semi-aggressive manner, in an undefined zone between the treatments for routine fungal ball and aggressive IFS.     

Influence of factor 5 rs6025 and factor 2 rs1799963 mutation on inhibitor development in patients with hemophilia A - an Israeli-German multicenter database study

Objective

The present cohort study was performed to investigate the impact of the factor 5 rs6025 [F5] and the factor 2 rs1799963 [F2] mutations on high-titer inhibitor development [HRI] in patients with severe/moderate-severe hemophilia A [HA].

Patients and Methods

216 patients with F8 < 2% born between 1980 and 2011 were followed after initial HA diagnosis over the first 200 exposure days. The first HA patient per family who presented for diagnosis was included in the present study.

Results

32 of 216 children [14.8%] tested for F5/F2 carried either the F5 or the F2 variant. HRI occurred in 14 out of 32 F5/F2-carriers compared with 40 of 184 without F5/F2. Multivariate analysis adjusted for F8 genotype, treatment intensity, first-line use of plasma derived FVIII versus recombinant FVIII concentrates revealed that the presence of F5/F2 independently increases the risk of HRI development to odds [OR] of 3.4. Large deletions in the F8 gene [OR: 5.10], patients from Israel [OR: 4.0], the increase of FVIII per one IU/kgbw [OR: 1.05] and birth year [OR: 1.12] were significantly associated with the risk to develop HRI.

Conclusion

Data presented here suggest that HRI development is of multifactorial origin and that F5 and F2 mutations may contribute to this risk.     

Interface Fluid Syndrome (IFS) following Toxic Anterior Segment Syndrome (TASS): not related to high intraocular pressure but to endothelial failure

We describe the case of a 52-year-old female with past history of LASIK, 21?years earlier, without Fuchs’ endothelial dystrophy, who underwent phacoemulsification and intraocular lens (IOL) implantation. During the early postoperative period severe corneal edema, anterior chamber cellularity and iris inflammation presented, accompanied by a clear space along the LASIK interface. Those findings were interpreted as part of a Toxic Anterior Segment Syndrome (TASS) and secondary interface fluid syndrome (IFS). When interface fluid was present, intraocular pressure (IOP) measured in the center of the cornea yielded very low values. In addition, applanation tonometry performed in the corneal periphery, as well as Schiotz tonometry and digital tonometry also indicated that the IOP was not high. Fluid in the interface persisted until a DMEK was carried out 11?months after the phacoemulsification surgery. Five days postoperatively the IFS resolved, confirmed by OCT imaging. The origin of IFS in this case was corneal edema secondary to endothelial cell dysfunction and it was not related to high IOP. This is the first reported case of IFS following TASS, the third case published of DMEK procedure used to solve endothelial failure-related IFS, and the case with the longest time of presentation after LASIK.     

Newborn length predicts early infant linear growth retardation and disproportionately high weight gain in a low-income population

Background

Stunting is prevalent by the age of 6 months in the indigenous population of the Western Highlands of Guatemala.

Aim

The objective of this study was to determine the time course and predictors of linear growth failure and weight-for-age in early infancy.

Study design and subjects

One hundred and forty eight term newborns had measurements of length and weight in their homes, repeated at 3 and 6 months. Maternal measurements were also obtained.

Results

Mean ± SD length-for-age Z-score (LAZ) declined from newborn − 1.0 ± 1.01 to − 2.20 ± 1.05 and − 2.26 ± 1.01 at 3 and 6 months respectively. Stunting rates for newborn, 3 and 6 months were 47%, 53% and 56% respectively. A multiple regression model (R² = 0.64) demonstrated that the major predictor of LAZ at 3 months was newborn LAZ with the other predictors being newborn weight-for-age Z-score (WAZ), gender and maternal education ∗ maternal age interaction. Because WAZ remained essentially constant and LAZ declined during the same period, weight-for-length Z-score (WLZ) increased from − 0.44 to + 1.28 from birth to 3 months. The more severe the linear growth failure, the greater WAZ was in proportion to the LAZ.

Conclusion

The primary conclusion is that impaired fetal linear growth is the major predictor of early infant linear growth failure indicating that prevention needs to start with maternal interventions.     

Comparison of the intakes of sugars by young children with and without dental caries experience

BACKGROUND: Relationships among sugars and dental caries in contemporary societies are unclear. The authors describe young children's intakes of nonmilk extrinsic (NME) and intrinsic/milk sugars and relate those intakes to dental caries. METHODS: The authors conducted cross-sectional analyses of dietary data collected from the Iowa Fluoride Study using three-day diaries for subjects at ages 1, 2, 3, 4 and 5 years and for subjects aged 1 through 5 years according to dental caries experience at 4.5 to 6.9 years of age. They categorized foods and beverages as containing NME or intrinsic/milk sugars. RESULTS: Subjects' total, NME, food NME and intrinsic/milk sugars intakes at ages studied did not differ between subjects with and without caries experience. Beverage NME sugars intakes at age 3 years predicted caries (P < .05) in logistic regression models adjusted for age at dental examination and for fluoride intake. CONCLUSIONS: Dental caries is a complex, multifactorial disease process dependent on the presence of oral bacteria, a fermentable carbohydrate substrate and host enamel. A simple NME-intrinsic/milk sugars categorization appears insufficient to capture the complex dietary component of the caries process. CLINICAL IMPLICATIONS: Cariogenicity is more likely a function of the food and/or beverage vehicle delivering the sugar and the nature of exposure-that is, frequency and length of eating events-than of the sugar's categorization.     

Cortical networks for motion processing: Effects of focal brain lesions on perception of different motion types

Neuropsychological studies in humans provide evidence for a variety of extrastriate cortical areas involved in visual motion perception. Multiple mechanisms underlying processing of different motion types have been proposed, however, support for cortical specialization has remained controversial so far. We therefore studied motion perception in 23 patients with focal lesions to various cortical areas and considered translational motion, heading from radial flow, as well as biological motion. Patients’ detection thresholds were compared with age-specific data from a large healthy control sample (n = 122). Elevated thresholds and significant threshold asymmetries between both visual hemifields were defined as deficits. Contrary to prevalent opinion, we found a high prevalence of motion deficits in our sample. Impairment was restricted to a specific motion type in 10 patients, whereas only a single patient showed a deficit for multiple motion types. Functional areas were determined by lesion density plots and by comparison between patients with and without a specific deficit. Results emphasize a dissociation between basic motion processing and processing of complex motion. Anatomical analysis confirmed critical occipito-temporo-parietal areas for perception of translational motion. In contrast, heading perception from radial flow proved to be remarkably robust to most lesions. We exclusively identified the frontal eye fields as a critical structure. Biological motion perception relied on distinct pathways involving temporal, parietal, and frontal areas. Although precise functional roles of identified areas cannot be determined conclusively, results clearly indicate regional specialization for motion types of different complexity. We propose a network for motion processing involving widely distributed cortical areas.