The synthesis of clickable polysaccharides was achieved by using alkynylated 1,6-anhydro glucopyranose as a monomer and BF3·OEt2 as an effective catalyst. Subsequent click conjugation with polyethylene glycol (PEG) afforded PEG-grafted polysaccharides in nearly quantitative efficiency.

Existing CAPTCHA solutions are a major source of user frustration on the Internet today, frequently forcing companies to lose customers and business. Game CAPTCHAs are a promising approach which may make CAPTCHA solving a fun activity for the user. One category of such CAPTCHAs – called Dynamic Cognitive Game (DCG) CAPTCHA – challenges the user to perform a game-like cognitive (or recognition) ...

CAPTCHA is widely used security technique employed to avoid automated form submissions or verify user as human. An alternative CAPTCHA method based on pattern matching and number recognition ability is proposed in this paper, which verifies user as human and prevents bots to intervene and spam applications or services. This method is based on user gestures which make it unique and secure. The b...

The synthesis of mesoporous silica nanoparticles bearing organic functionalities is strained by the careful adjustment of the reaction parameters, as the incorporation of functional and/or voluminous organosilanes during the sol-gel synthesis strongly affects the final structure of the nanoparticles. In this paper we describe the design of new clickable mesoporous silica nanoparticles as sphere...

Cloud computing is simply a metaphor for the internet. User does not required knowledge, control, and ownership in the computer infrastructure. User simply access or rent the software and paying only for what they use. Advantage of cloud computing is huge like Broad network access, Cost effectiveness, Rapid elasticity, Measured services, On-Demand service, Resource pooling, Location independenc...

We present a technique for using a content-based video labeling task as a CAPTCHA. Our video CAPTCHAs are generated from YouTube videos, which contain labels (tags) supplied by the person that uploaded the video. They are graded using a video’s tags, as well as tags from related videos. In a user study involving 184 participants, we were able to increase the average human success rate on our vi...

A clickable and cell-permeable affinity-based probe (AfBP) was designed from staurosporine, by incorporating an electrophilic chloroacetamide warhead to facilitate in situ proteome labeling of a range of potential kinase targets.

Human Interactive Proofs (HIPs) are automatic reverse Turing tests designed to distinguish between various groups of users. Completely Automatic Public Turing test to tell Computers and Humans Apart (CAPTCHA) is a HIP system that distinguish between humans and malicious computer programs. Many CAPTCHAs have been proposed in the literature that text-graphical based, audio-based, puzzle-based and...