A high-capacity coverless image steganography method based on double-level index and block matching.

Recently, a new information hiding technology called coverless information steganography (CIS) is proposed, which uses the original natural image as stego image for the transmission of secret information which can resist the detection of image steganalysis algorithm, so it received extensive attention and support. However, it is still a low hidden capacity of the CIS methods up to now. This paper proposes a high-capacity coverless information steganography technology. In which we divide the cover image into several image blocks and every image block can represent one bit secret information which improves the capacity greatly. Then we retrieve the image blocks for replacement from the image block database based on secret information and then synthesize them into stego image. The quality of the stego image is still high because the required image blocks are similar to cover image blocks and they are all from natural images. Moreover, in order to improve the retrieval efficiency, we have established a double-level index structure. The experimental results show that compared with the existing CIS methods, the proposed method has larger capacity and better visual quality.

[A3-A3 side-to-side anastomosis combined with endovascular intervention in recurrent complex anterior artery aneurysm: a case report and literature review].

A 28-year-old female patient was admitted to the Second Affiliated Hospital, Zhejiang University School of Medicine, with sudden headache and vomiting for 1 day. CT scan conducted at emergency revealed subarachnoid hemorrhage, whereas digital subtraction angiography demonstrated a wide-neck aneurysm located at A1 segment of the left anterior cerebral artery. The aneurysm was totally coiled using stent assistance, which, however, was recanalized at 3 month follow-up. This patient was then subjected to aneurysm and parent artery occlusion after bypass of the bilateral A3 segments, who recovered well and discharged without ischemic complications.

The feasibility and efficacy of endovascular treatment for very small or tiny ruptured paraclinoid aneurysms.

INTRODUCTION: The aim of this study was to evaluate the feasibility of endovascular treatment (EVT) for ruptured very small (≤5 mm) or tiny (≤3 mm) paraclinoid aneurysms of the internal carotid artery (ICA). METHODS: From November 2009 to April 2012, 32 ruptured paraclinoid aneurysms (very small, 23; tiny, 9) in 31 patients received EVT. Angiographic follow-up determined occlusion rates which were classified as total/near-total (95-100 %), subtotal (80-95 %), and partial (<80 %) occlusions. Follow-up data were retrospectively analyzed and categorized using the Modified Rankin Scale (mRS). RESULTS: Based on our paraclinoid aneurysm classification, 25 % (8) were classified as type I, 46.9 % (15) as type II, and 28.1 % (9) as type III. EVT was technically successful in 96.8 % (31), with coiling only in 12.5 % (4), balloon remolding coiling in 6.3 % (2), and stent-assisted coiling in 78.1 % (25). Total/near-total occlusion was immediately achieved in 34.4 % (11), subtotal occlusion in 37.5 % (12), and partial occlusion in 28.1 % (9). Follow-up angiography (mean, 9.9 ± 6.4 months) revealed total/near-total occlusion in 50 % (16) aneurysms, subtotal in 31.3 % (10), and partial occlusion in 18.8 % (6). At the end of clinical follow-up (mean, 14.8 ± 9.5 months), it revealed an mRS grade 0 in 38.7 % (12) of patients, grade 1 in 25.8 % (8), grade 2 in 22.6 % (7), grade 3 in 6.5 % (2), grade 4 in 3.2 % (1), and grade 5 in 3.2 % (1). CONCLUSION: EVT is feasible and effective for ruptured very small or tiny paraclinoid aneurysms of the ICA.

[Early management of intracranial ruptured vertebral dissecting aneurysms].

OBJECTIVE: To evaluate the early management of intracranial ruptured vertebral dissecting aneurysms. METHODS: Twenty-two patients with ruptured vertebral dissecting aneurysms were managed by various treatment modalities according to their conditions. One aneurysm was treated by proximal vertebral artery coiling, 15 aneurysms by aneurysm and parent artery coiling, and 5 aneurysms by stent-assisted coiling (4 of 5 by stent-within-a-stent technique), one by single double-stent. Bloody cerebrospinal fluid was drained by postoperative lumbar subarachnoid drainage in order to prevent cerebral vasospasm. RESULTS: All 22 cases were successful without bleeding complication during the operation.There was 1 case of early postoperative non-aneurysmal hemorrhage, 2 cases of posterial group cranial nerves palsies, 1 case harbored Hunt & Hess IV who gave up treatment. After follow-up for 3-18 months, there was no rebleeding and infarction. Twenty patients recovered well, except 1 having posterial group cranial nerves palsies. Fourteen cases were followed up by angiography. In 3 patients treated by stent-assisted coiling, DSA showed that aneurysms disappeared and loading vessel passed freely.DSA of 11 cases with aneurysm and parent artery coiling demonstrated complete obliteration of the dissection without aneurysm imaging. CONCLUSION: Early endovascular treatment of ruptured vertebral dissecting aneurysms is essential. The selective method of endovascular management according to the characteristics of aneurysm is safe and effective. Double stent-assisted coiling should be the first choice.

[National surveillance of schistosomiasis in China from 2000 to 2004].

OBJECTIVE: To specify the trends of endemic situation among twenty one national surveillance sites for schistosomiasis from 2000 to 2004. METHODS: According to the national surveillance protocol, longitudinal surveillance on endemic situation of schistosomiasis was carried out at twenty-one sites since 2000. RESULTS: The infection rate of Schistosoma japonicum declined in six of the twenty-one surveillance sites. The density of living snails and of infected snails decreased in two sites but not well controlled in most other sites. The prevalence in cattle fluctuated yearly in most sites and maintained at a relatively high level. During the surveillance period, acute cases were found annually and the number of advanced patients did not increase significantly. No new case and infected snails were found in Jinshan, Shanghai, since 2000, where transmission of schistosomiasis was interrupted two decades ago. CONCLUSION: Routine control strategies such as selective chemotherapy combined with livestock chemotherapy, snail control in risk areas have a positive impact on the control of schistosomiasis. However, these strategies should be lasted for longer time and the surveillance on snails and cattle should be continued.

Surveillance for schistosomiasis japonica in China from 2000 to 2003.

According to the protocol of the national surveillance project, longitudinal observation of the endemic situation of schistosomiasis japonica in China has been carried out at 20 sentinel surveillance sites, commencing in 2000. After four years of surveillance, the infection rate of Schistosoma japonicum gradually decreased in seven sentinel sites. In 10 sites, infection rates remained relatively stable over time, while there was a marked increase in one site. No clear trend became apparent in the remaining two sites. Significant reductions of densities of living intermediate host snails and infected snails were noted in only two sites. In turn, the endemic situation was not well controlled in most of the other sentinel sites. The infection cattle rate fluctuated yearly in the majority of the sites and maintained a high level. During the four years of surveillance, acute cases of schistosomiasis japonica among humans were found in each of the yearly cross-sectional surveys, and the number of patients with advanced schistosomiasis did not change significantly. The surveillance results obtained thus far indicate that current control strategies continue to reduce morbidity due to schistosomiasis. However, concerted control efforts must continue for a long time and the surveillance of intermediate host snail and animal reservoirs (e.g. cattle) should be strengthened.

An economic evaluation of the national schistosomiasis control programme in China from 1992 to 2000.

The World Bank Loan Project, by far the largest effort in China for schistosomiasis control since control activities were initiated in the mid 1950s, was carried out for a 9-year period commencing in 1992 in the 8 provinces where Schistosoma japonicum remained endemic when the project started. To evaluate its impact, a retrospective economic evaluation was done in 2001. Six representative counties, i.e. Huarong in Hunan province, Qianjiang in Hubei province, Yugan in Jiangxi province, Tongling in Anhui province, Xichang in Sichuan province and Dali in Yunnan province, were selected for the study. The total financial input in these counties from 1992 to 2000 was RMB Yuan 90.334 million with the World Bank loan accounting for 40.9%. Control efforts resulted in reduction of human prevalence rates in the six counties from 0.7-9.0% in 1992 to 0.1-2.7% in 2000. With regard to S. japonicum infection in bovines, a high reduction was observed in Qianjiang, and smaller decreases were noted in four counties, while there was an increase in Dali. In general, the areas infested by the intermediate host snail fluctuated around the initial level. The net benefit-cost ratio was 6.20, which means that this project gained US$ 6.20 for every dollar spent. The correlation coefficients of the net benefit-cost ratio to the human and bovine infection rates at the beginning of the project were 0.55 and 0.66, respectively. It is conceivable that further progress in schistosomiasis control is an important feature for sustained growth of the local economy, particularly in areas where control of the disease has been most challenging.

The public health significance and control of schistosomiasis in China--then and now.

The description of schistosomiasis in China dates back more than two millennia. The disease caused social and economic hardship, and the rates of morbidity and mortality were high. In the mid 1950s, when China's population was approximately 600 million, an estimated 11.6 million people were infected with Schistosoma japonicum. Hence, a national control programme was launched, with an emphasis on intermediate host snail control by means of environmental management. Over the past 50 years, the national control programme has made great progress and praziquantel-based morbidity control became the mainstay of control. In 2000, the number of infected people had been reduced to an estimated 694,788, the snail-infested area has been abridged by over 75%, and the disease had been eliminated in five of the 12 previously endemic provinces. Between the mid 1980s and 2003, the criteria of transmission interruption have been reached in 260 counties (60.0%), transmission control has been achieved in 63 counties (14.5%), but the disease was still endemic in the remaining 110 counties (25.4%). Comparison between the number of cases in 2000 and 2003 suggests that schistosomiasis has re-emerged; an estimated 843,011 people were infected with S. japonicum in 2003. Here, we provide a short historical account of the pubic health significance of schistosomiasis in China, highlight the progress made to date with the national control programme, and place particular emphasis on the most recent trends. Finally, we discuss remaining challenges for schistosomiasis control with the ultimate goal of disease elimination.

[National surveillance of schistosomiasis from 2000 to 2002].

OBJECTIVE: To identify the trends of endemic situation at the twenty-one national surveillance sites from 2000 to 2002. METHODS: According to the protocol of the national surveillance system, longitudinal surveillance of endemic situation of schistosomiasis was carried out at the twenty-one surveillance sites since 2000. RESULTS: Relative indexes of endemic situation of schistosomiasis decreased in two surveillance sites annually. The infection rate of Schistosoma japonicum in human population decreased in most surveillance sites. The infection rate of cattle decreased in eight surveillance sites. However, acute cases were found in two sites each year. The density of live snails and infected snails was higher compared with that in 2000 among eight sites and infected snails were found in inner embankment in Junshan surveillance sites. Hunan Province, in 2002 at first time. The snail ridden areas increased significantly in Fengjin sites, Shanghai, where schistosomiasis was eliminated years ago. CONCLUSION: Current control strategies have some impact on the morbidity of schistosomiasis. However, these strategies should be lasted for longer time and surveillance on snails should be enhanced.

[Study on the intention of the administrative model of anti-schistosomiasis institutions at county level].

OBJECTIVE: To investigate current status of schistosomiasis control system at the county level and make recommendations to improve the infrastructure adapting to the prevalent condition of the disease. METHODS: Through pertinently sampling and semi-quantitative questionnaire among the professional workers, experts and administrators in schistosomiasis control, the primary weaknesses involved in the management system and human resources were analyzed. RESULTS: 380 questionnaires were distributed, 33 out of 40 were returned from experts/administrators and 285 out of 340 were received from the professionals. In general, the participants acknowledged the effectiveness of the mechanism on anti-schistosomiasis campaign during the past 40 years. It was found that lack of funds for schistosomiasis control and the poor administrative model of anti-schistosomiasis activities were the main barriers to the control. About half of the participants agreed that the policy about merging the county level anti-schistosomiasis facilities into the Center for Disease Prevention and Control (CDPC) system. The study also showed an inbalanced distribution of the manpower for schistosomiasis control across the endemic regions. The dropout rate of human resources was high due to the poor management and welfare. CONCLUSION: Reforms on the management model should be performed and multiform compensation system should be built in accordance with the prevalence and trends of schistosomiasis.