A comparative study of blood viscometers of 3 different types.

 The greater the viscosity of the blood, the more difficult its flow becomes, leading to an increased incidence of diseases caused by blood circulation disorders. These diseases are commonly associated with the cardiovascular and cerebrovascular systems. High blood viscosity is a primary cause of circulatory system diseases. Studies have shown that accurately measuring blood viscosity and applying this data in clinical trials can help prevent circulatory system diseases. Viscosity data can vary depending on the measurement methods used, even when these methods are based on hydrodynamic principles. Despite using approved blood viscometers, the results often differ depending on the type of viscometer used, potentially causing confusion within the medical field. Informing the medical community about these differences and the level of error associated with each measurement method can help reduce this confusion. To our knowledge, the degree of difference in viscosity measurement results due to different measurement methods and the reasons for these differences have not yet been thoroughly explored. In this study, we selected three blood viscosity measurement methods registered with the Ministry of Food and Drug Safety of Korea to analyze the same canine blood. The viscosity measurements were carried out using each device and compared. The parallel plate and scanning capillary methods yielded similar viscosity values, while the cone plate method showed lower viscosity values. The viscosity of blood, as measured by the three viscometers, differed, indicating that more experimental data must be accumulated to evaluate the cause of these differences. In this paper, we identified several causes of inconsistency and suggested measures to avoid this confusion. However, confirming that the test results show systematic differences is expected to assist clinicians who diagnose and prescribe treatments based on blood viscosity results. The findings of this comparative study are anticipated to serve as a starting point for establishing guidelines or standards for blood viscosity measurement methods.

Direct Solution-Phase Synthesis and Functionalization of 2D WSe2 for Ambient Stability.

2H phase tungsten diselenide (WSe2 ) is a p-type 2D semiconductor from the transition metal dichalcogenides (TMDs) family with unique optoelectrical properties. Solution phase production of atomically thin WSe2 is challenging due to its instability under ambient conditions. We present a highly efficient and scalable solution method for simultaneously exfoliating and functionalizing WSe2 by leveraging the non-covalent interaction between mercapto-group and bulk WSe2 . Single and few-layer 2H phase pure WSe2 sheets of lateral size up to 5 µm with minimal basal plane defects, as revealed by XPS, Raman and FTIR spectroscopy, are produced in a water-ethanol mixture. Remarkably, WSe2 dispersion remains stable even at high concentrations (10 mg/mL) and exhibited high colloidal stability with a shelf-life exceeding a year. The findings from our study suggest that through precise manipulation of intercalation chemistry, mass production of solution-processable phase-sensitive 2D materials such as WSe2 can be achieved. This advancement holds great potential for facilitating their practical utilization in various real-world applications.

Environmentally friendly quantum-dot color filters for ultra-high-definition liquid crystal displays.

This work reports the synthesis and application of highly tuned cadmium-free green and red InPZnSe1-xSx/ZnS quantum dots (QDs) in QD enhanced liquid crystal displays (LCD). The emissions of the quantum dots were synthetically tuned to sharp emissions at low full-width at half maximum. The QDs were incorporated in LCD devices as quantum dot enhancement film (QDEF) or as a quantum dot incorporated color filter (QDCF). Synthetic tuning of the gradient inter-shell in the QDs leads to reduced full width at half-maximum, resulting in sharp green and red emissions from both types of devices. The application of the same QDs to devices using these different integration techniques shows the superiority of QDCF devices over QDEF ones. The RGB color gamut of a QDCF-LCD was 81.4% of REC.2020 in the CIE 1931 color space compared to 71.2% obtained for a QDEF-LCD display. The improved performance of QDCF was mainly due to the optimal interactions between the green QDs and the green color filter. The superior performance of cadmium-free InPZnSe1-xSx/ZnS QDCFs in LCDs make them well-suited for ultra-high-definition TV formats.

A citizen science initiative for open data and visualization of COVID-19 outbreak in Kerala, India.

OBJECTIVE: India reported its first coronavirus disease 2019 (COVID-19) case in the state of Kerala and an outbreak initiated subsequently. The Department of Health Services, Government of Kerala, initially released daily updates through daily textual bulletins for public awareness to control the spread of the disease. However, these unstructured data limit upstream applications, such as visualization, and analysis, thus demanding refinement to generate open and reusable datasets. MATERIALS AND METHODS: Through a citizen science initiative, we leveraged publicly available and crowd-verified data on COVID-19 outbreak in Kerala from the government bulletins and media outlets to generate reusable datasets. This was further visualized as a dashboard through a front-end Web application and a JSON (JavaScript Object Notation) repository, which serves as an application programming interface for the front end. RESULTS: From the sourced data, we provided real-time analysis, and daily updates of COVID-19 cases in Kerala, through a user-friendly bilingual dashboard (https://covid19kerala.info/) for nonspecialists. To ensure longevity and reusability, the dataset was deposited in an open-access public repository for future analysis. Finally, we provide outbreak trends and demographic characteristics of the individuals affected with COVID-19 in Kerala during the first 138 days of the outbreak. DISCUSSION: We anticipate that our dataset can form the basis for future studies, supplemented with clinical and epidemiological data from the individuals affected with COVID-19 in Kerala. CONCLUSIONS: We reported a citizen science initiative on the COVID-19 outbreak in Kerala to collect and deposit data in a structured format, which was utilized for visualizing the outbreak trend and describing demographic characteristics of affected individuals.

Exploring Orbit-Orbit Interaction in Relationship to Photoluminescence Quantum Efficiency in Perovskite Quantum Dots through Rashba Effect.

This study demonstrates the influence of the orbit-orbit interaction on the photoluminescence quantum efficiency (PLQE) of metal halide perovskite quantum dots (QDs) through the Rashba effect. The orbit-orbit interaction between excitons was characterized by using the minimal excitation intensity required to generate a photoluminescence difference (ΔPL) between linearly and circularly polarized photoexcitations. It was observed that changing the surface functionalization from PFOA-OA to PFSH-OAm and OA can largely increase the minimal excitation intensity for generating ΔPL. This indicates that the orbit-orbit interaction is essentially decreased in CsPbBr1I2 QDs with surface functionalization. Simultaneously, the PLQE is increased from 39% to 59 and 72% in CsPbBr1I2 QDs upon surface functionalization. Furthermore, the PL lifetime is decreased with increasing the PLQE in CsPbBr1I2 QDs upon surface functionalization. This phenomenon implies that decreasing the orbit-orbit interaction can essentially weaken the Rashba effect and consequently reduce the disallowed transitions, leading to an enhancement in the PLQE in perovskite QDs.

Multiwall carbon nanotube reinforced teflon fibrils for oil spill clean up and its effective recycling as textile dye sorbent.

Surface functionalized multiwall carbon nanotube (MWCNT) reinforced teflon fibrils (MWCNT@Teflon) were successfully tested as an - oil - absorbent that can be used as a potential oil recovery material at the time of oil spill accidents in water. We found that oleic acid functionalization of MWCNTs was important for their adhesion onto teflon fibrils and at the same time prevented the MWCNT leaching into oil/water interface. The fibrils had displayed superior mechanical and thermal stability and provided a new insight to oil spill clean-up applications with easy recovery of absorbed oil by simple squeezing. Recycling of exhausted MWCNT@Teflon fibrils after oil recovery applications was conducted by pyrolysis under inert atmosphere in presence of magnetic clay. The magnetic clay absorbed the pyrolysis products, resulting in a heterostructured magnetic clay carbon composite (MCC) which was found super paramagnetic and chemically stable in all pH. The MCC was found capable of adsorbing textile dye from water ultra-fast with in a maximum contact time of 2 min and magnetically separable after adsorption experiments.

Simultaneous Graphite Exfoliation and N Doping in Supercritical Ammonia.

We report the exfoliation of graphite and simultaneous N doping of graphene by two methods: supercritical ammonia treatment and liquid-phase exfoliation with NH4OH. While the supercritical ammonia allowed N doping at a level of 6.4 atom % in 2 h, the liquid-phase exfoliation with NH4OH allowed N doping at a level of 2.7 atom % in 6 h. The N doped graphene obtained via the supercritical ammonia route had few layers (<5) and showed large lateral flake size (∼8 µm) and low defect density (ID/IG < 0.6) in spite of their high level of N doping. This work is the first demonstration of supercritical ammonia as an exfoliation agent and N doping precursor for graphene. Notably, the N doped graphene showed electrocatalytic activity toward oxygen reduction reaction with high durability and good methanol tolerance compared to those of commercial Pt/C catalyst.

Photosensitive functionalized surface-modified quantum dots for polymeric structures via two-photon-initiated polymerization technique.

In this paper, the surface modification of CdSe- and CdZnS-based quantum dots (QDs) with a functional silica shell is reported. Functionalized silica shells are prepared by two routes: either by ligand exchange and a modified Stöber process or by a miniemulsion process with amphiphilic poly(oxyethylene) nonylphenylether also know as Igepal CO-520 (IG) as oligomeric amphiphile and modified silica precursors. The polymerizable groups on the functionalized silica shell allow covalent bonding to a polymer matrix and prevent demixing during polymerization and crosslinking. This allows the homogeneous incorporation of QDs in a crosslinked polymer matrix. This paper furthermore demonstrates that the resulting QDs, which are i) shielded with a proper silica shell and ii) functionalized with crosslinkable groups, can be used in two-photon-initiated polymerization processes in combination with different photoresists to obtain highly luminescent 3D structures. The resulting luminescent structures are attractive candidates for photonics and metamaterials research.

Energy and charge transfer in nanoscale hybrid materials.

Hybrid materials composed of colloidal semiconductor quantum dots and π-conjugated organic molecules and polymers have attracted continuous interest in recent years, because they may find applications in bio-sensing, photodetection, and photovoltaics. Fundamental processes occurring in these nanohybrids are light absorption and emission as well as energy and/or charge transfer between the components. For future applications it is mandatory to understand, control, and optimize the wide parameter space with respect to chemical assembly and the desired photophysical properties. Accordingly, different approaches to tackle this issue are described here. Simple organic dye molecules (Dye)/quantum dot (QD) conjugates are studied with stationary and time-resolved spectroscopy to address the dynamics of energy and ultra-fast charge transfer. Micellar as well as lamellar nanostructures derived from diblock copolymers are employed to fine-tune the energy transfer efficiency of QD donor/dye acceptor couples. Finally, the transport of charges through organic components coupled to the quantum dot surface is discussed with an emphasis on functional devices.

Synthesis and photophysical properties of two-photon absorbing spirofluorene derivatives.

New spirofluorene-based quadrupolar two-photon absorbing dyes having triphenylamine and N,N-dibutylaniline as electron donors at the end of molcules were designed and synthesized. The third-order nonlinear optical properties of these compounds were studied using a two-photon excited fluorescence method. They were found to have high two-photon absorption cross-section owing to extended conjugation of the spirofluorene moiety. The effect of varying the donor strength could be discerned by comparing the two compounds. They were successfully used as a photosensitizers for two-photon initiated polymerization of three-dimensional micro-objects.

Degenerate multi-photon properties of spirofluorene derivatives.

Two- and three-photon absorption properties of the fluorene-based chromophores have been investigated. The two- and three-photon absorption cross-section are found to be increased with the strength of the electron donor groups in the order of N-ethylcarbazoyl (1), triphenylamino (2), and N,N-dibutylanilino (3) groups. This nonlinear absorption enhancement can be interpreted by the increase of intramolecular charge transfer facilitated by strong electron donors and the decreased detuning energy (deltaE). Furthermore, direct laser microfabrication by two-photon photopolymerization with compound 2 as a two-photon sensitizer was carried out. Laser exposure time-dependent lateral voxel size has also been studied.

Photopatternable quantum dots forming quasi-ordered arrays.

We have functionalized core-shell CdSe/ZnS quantum dots (QDs) with a photosensitive monolayer, rendering them solution processable and photopatternable. Upon exposure to ultraviolet radiation, films composed of this material were found to polymerize, forming interconnected arrays of QDs. The photoluminescence properties of the nanocrystal films increased with photocuring. The material was found to be suitable for spin casting and was used as the active layer in a green electroluminescent device. The electroluminescence efficiency of devices containing a photocured active layer was found to be largely enhanced when compared to devices containing nonphotocured active layers. The material also showed excellent adhesion to both organic and inorganic substrates because of the unique combination of a siloxane and a photopatternable layer as ligands. The pristine functionalized nanocrystals could easily be used for two-dimensional patterning on organic and inorganic substrates. The photopatternable quantum dots were uniformly dispersed into a photopolymerizable resin to fabricate QD embedded three-dimensional microstructures.