The growing prevalence of counterfeit products worldwide poses serious threats to economic securi... more The growing prevalence of counterfeit products worldwide poses serious threats to economic security and human health. Developing advanced encryption materials with physical unclonable functions offers an attractive defense against counterfeiting. Here, we have successfully developed multimodal, dynamic and unclonable anti-counterfeiting labels based on high-quality diamond microparticles containing silicon-vacancy (SiV) centers. These chaotic microparticles were heterogeneously grown on silicon substrate by chemical vapor deposition, facilitating scalable and massive fabrication at low cost. Due to the non-deterministic nature of this growth method, the intrinsically unclonable function has been introduced by the randomized features of each individual particle. In particular, the extremely stable signals of SiV photoluminescence (PL) and light scattering from diamond microparticles are shown to enable high-capacity optical encryption. Moreover, time-dependent encryption has been ach...
By measuring ODMR spectrum of NV centers and PL spectrum of SiV centers simultaneously, we demons... more By measuring ODMR spectrum of NV centers and PL spectrum of SiV centers simultaneously, we demonstrate high-precision optical thermometry using two independent mechanisms cross-validating each other in a diamond sample with dual-defect centers.
Diamond microparticles containing SiV centers with superior properties are fabricated on a Si sub... more Diamond microparticles containing SiV centers with superior properties are fabricated on a Si substrate by CVD using salt-assisted air-oxidized nanodiamond seeds. Ultrasensitive all-optical thermometry is demonstrated by the high-quality sample.
The growing prevalence of counterfeit products worldwide poses serious threats to economic securi... more The growing prevalence of counterfeit products worldwide poses serious threats to economic security and human health. Developing advanced anti-counterfeiting materials with physical unclonable functions offers an attractive defense strategy. Here, we report multimodal, dynamic and unclonable anti-counterfeiting labels based on diamond microparticles containing silicon-vacancy centers. These chaotic microparticles are heterogeneously grown on silicon substrate by chemical vapor deposition, facilitating low-cost scalable fabrication. The intrinsically unclonable functions are introduced by the randomized features of each particle. The highly stable signals of photoluminescence from silicon-vacancy centers and light scattering from diamond microparticles can enable high-capacity optical encoding. Moreover, time-dependent encoding is achieved by modulating photoluminescence signals of silicon-vacancy centers via air oxidation. Exploiting the robustness of diamond, the developed labels e...
Journal of Membrane and Separation Technology, 2013
Periodontal regeneration is the restoration of lost periodontium or supporting tissues and includ... more Periodontal regeneration is the restoration of lost periodontium or supporting tissues and includes the formation of new alveolar bone, new cementum and new periodontal ligament. The concept of GTR is based on the exclusion of gingival connective tissue cells and prevention of epithelial down growth into the wound, thereby allowing cells with regenerative potential (PDL and bone cells) to enter the wound first. GTR consists of placing barriers of different types to cover the bone and periodontal ligament thus temporarily separating them from gingival epithelium. Excluding the epithelium and gingival connective tissue from the root surface during the post-surgical healing phase not only prevent epithelial migration into the wound but also favors repopulation of the area by cells from the periodontal ligament and bone. Purpose and Scope-This review discusses the rationale for using guided tissue regeneration therapy. The review not only attempts to clarify the concept of selective tissue regeneration using non-resorbable and resorbable barriers, but to discuss differences in healing events after treatment with the two types of barriers together with their significance in periodontal therapy. At present, barrier membranes have potential clinical use in promoting periodontal tissue regeneration if patients to be so treated are selected appropriately. Research is still necessary to determine the critical period for guiding the ingrowth of new attachment forming cells and also to further clarify the concept of GTR involving the "wrong cell type" which inhibits periodontal tissue regeneration.
The growing prevalence of counterfeit products worldwide poses serious threats to economic securi... more The growing prevalence of counterfeit products worldwide poses serious threats to economic security and human health. Developing advanced encryption materials with physical unclonable functions offers an attractive defense against counterfeiting. Here, we have successfully developed multimodal, dynamic and unclonable anti-counterfeiting labels based on high-quality diamond microparticles containing silicon-vacancy (SiV) centers. These chaotic microparticles were heterogeneously grown on silicon substrate by chemical vapor deposition, facilitating scalable and massive fabrication at low cost. Due to the non-deterministic nature of this growth method, the intrinsically unclonable function has been introduced by the randomized features of each individual particle. In particular, the extremely stable signals of SiV photoluminescence (PL) and light scattering from diamond microparticles are shown to enable high-capacity optical encryption. Moreover, time-dependent encryption has been ach...
By measuring ODMR spectrum of NV centers and PL spectrum of SiV centers simultaneously, we demons... more By measuring ODMR spectrum of NV centers and PL spectrum of SiV centers simultaneously, we demonstrate high-precision optical thermometry using two independent mechanisms cross-validating each other in a diamond sample with dual-defect centers.
Diamond microparticles containing SiV centers with superior properties are fabricated on a Si sub... more Diamond microparticles containing SiV centers with superior properties are fabricated on a Si substrate by CVD using salt-assisted air-oxidized nanodiamond seeds. Ultrasensitive all-optical thermometry is demonstrated by the high-quality sample.
The growing prevalence of counterfeit products worldwide poses serious threats to economic securi... more The growing prevalence of counterfeit products worldwide poses serious threats to economic security and human health. Developing advanced anti-counterfeiting materials with physical unclonable functions offers an attractive defense strategy. Here, we report multimodal, dynamic and unclonable anti-counterfeiting labels based on diamond microparticles containing silicon-vacancy centers. These chaotic microparticles are heterogeneously grown on silicon substrate by chemical vapor deposition, facilitating low-cost scalable fabrication. The intrinsically unclonable functions are introduced by the randomized features of each particle. The highly stable signals of photoluminescence from silicon-vacancy centers and light scattering from diamond microparticles can enable high-capacity optical encoding. Moreover, time-dependent encoding is achieved by modulating photoluminescence signals of silicon-vacancy centers via air oxidation. Exploiting the robustness of diamond, the developed labels e...
Journal of Membrane and Separation Technology, 2013
Periodontal regeneration is the restoration of lost periodontium or supporting tissues and includ... more Periodontal regeneration is the restoration of lost periodontium or supporting tissues and includes the formation of new alveolar bone, new cementum and new periodontal ligament. The concept of GTR is based on the exclusion of gingival connective tissue cells and prevention of epithelial down growth into the wound, thereby allowing cells with regenerative potential (PDL and bone cells) to enter the wound first. GTR consists of placing barriers of different types to cover the bone and periodontal ligament thus temporarily separating them from gingival epithelium. Excluding the epithelium and gingival connective tissue from the root surface during the post-surgical healing phase not only prevent epithelial migration into the wound but also favors repopulation of the area by cells from the periodontal ligament and bone. Purpose and Scope-This review discusses the rationale for using guided tissue regeneration therapy. The review not only attempts to clarify the concept of selective tissue regeneration using non-resorbable and resorbable barriers, but to discuss differences in healing events after treatment with the two types of barriers together with their significance in periodontal therapy. At present, barrier membranes have potential clinical use in promoting periodontal tissue regeneration if patients to be so treated are selected appropriately. Research is still necessary to determine the critical period for guiding the ingrowth of new attachment forming cells and also to further clarify the concept of GTR involving the "wrong cell type" which inhibits periodontal tissue regeneration.
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Papers by Madhav Gupta