Study on Color Quantitative Expression, Replication and Color Origin of Gray-Purple Nephrite from Qinghai, China Based on Spectroscopy Methods.

Color is one of the most important factors in evaluating the quality and price of jewelry. Quantitative research on color of jewels has been a hotspot in gemological science. Whether for jewelry industry or gems research, observing and describing the gems' color characteristics under transmission light is an essential method. This study focuses on building a research method to quantitatively characterize nephrite color, and to determine their color origin based on transmitted spectroscopy techniques. Natural gray-purple nephrite of Sanchahe mining, Qinghai, China was chosen as a typical subject due to its gradual-change color characteristic. We first quantitatively expressed and replicated the different color region on a gray-purple nephrite sample with given thickness (1.0 mm) with UV-Visible absorption spectra and 1976 CIE L*a*b* colorimetric parameters, as well as Adobe Photoshop software. The replicated color of light and dark color regions were both close to the transmitted color observed by naked eyes. It is inferred that the subtle color differences between naked eyes observation and transmitted spectroscopy replication may from the multiple effects of incident light in translucent polycrystalline structure, such as absorption, refraction, diffraction, scattering, and so on. As for the purple color origin, Laser Ablation Inductively Coupled Plasma Mass Spectroscopy (LA-ICP-MS) showed an increase of the concentrations of manganese (Mn) as the nephrite color becomes darker. Moreover, the emission peak at 585 nm on Photoluminescence (PL) and absorption peak at 530 nm on Ultraviolet Visible (UV-Vis), and the sextet Mn2+ resonance peaks on Electronic Paramagnetic Resonance (EPR) provide solid support to prove that Mn2+ should be the main factor contributing to the purple color. This work provides a specific experimental method on quantitative observing and describing the color of gems under transmitted light, and it also offers valuable information on determining the chromophores and color origin.

Ultrahigh Energy and Power Densities of d-MXene-Based Symmetric Supercapacitors.

Here, rational design electrodes are fabricated by mixing MXene with an aqueous solution of chloroauric acid (HAuCl4). In order to prevent MXene from self-restacking, the groups of -OH on the surface of Ti3C2Tx nanosheets underwent a one-step simultaneous self-reduction from AuCl4-, generating spaces for rapid ion transit. Additionally, by using this procedure, MXene's surface oxidation can be decreased while preserving its physio-chemical properties. The interlayered MX/Au NPs that have been obtained are combined into a conducting network structure that offers more active electrochemical sites and improved mass transfer at the electrode-electrolyte interface, both of which promote quick electron transfer during electrochemical reactions and excellent structural durability. The Ti3C2Tx-AuNPs film thus demonstrated a rate performance that was preferable to that of pure Ti3C2Tx film. According to the results of the characterization, the AuNPs effectively adorn the MXene nanosheets. Due to the renowned pseudocapacitance charge storage mechanism, MXene-based electrode materials also work well as supercapacitors in sulfuric acid, which is why MXene AuNPs electrodes have been tested in 3 M and 1 M H2SO4. The symmetric supercapacitors made of MXene and AuNPs have shown exceptional specific capacitance of 696.67 Fg-1 at 5 mVs-1 in 3 M H2SO4 electrolyte, and they can sustain 90% of their original capacitance for 5000 cycles. The highest energy and power density of this device, which operates within a 1.2 V potential window, are 138.4 Wh kg-1 and 2076 W kg-1, respectively. These findings offer a productive method for creating high-performance metal oxide-based symmetric capacitors and a straightforward, workable approach for improving MXene-based electrode designs, which can be applied to other electro-chemical systems that are ion transport-restricted, such as metal ion batteries and catalysis.

Next-generation graphene oxide additives composite membranes for emerging organic micropollutants removal: Separation, adsorption and degradation.

In the past two decades, membrane technology has attracted considerable interest as a viable and promising method for water purification. Emerging organic micropollutants (EOMPs) in wastewater have trace, persistent, highly variable quantities and types, develop hazardous intermediates and are diffusible. These primary issues affect EOMPs polluted wastewater on an industrial scale differently than in a lab, challenging membranes-based EOMP removal. Graphene oxide (GO) promises state-of-the-art membrane synthesis technologies and use in EOMPs removal systems due to its superior physicochemical, mechanical, and electrical qualities and high oxygen content. This critical review highlights the recent advancements in the synthesis of next-generation GO membranes with diverse membrane substrates such as ceramic, polyethersulfone (PES), and polyvinylidene fluoride (PVDF). The EOMPs removal efficiencies of GO membranes in filtration, adsorption (incorporated with metal, nanomaterial in biodegradable polymer and biomimetic membranes), and degradation (in catalytic, photo-Fenton, photocatalytic and electrocatalytic membranes) and corresponding removal mechanisms of different EOMPs are also depicted. GO-assisted water treatment strategies were further assessed by various influencing factors, including applied water flow mode and membrane properties (e.g., permeability, hydrophily, mechanical stability, and fouling). GO additive membranes showed better permeability, hydrophilicity, high water flux, and fouling resistance than pristine membranes. Likewise, degradation combined with filtration is two times more effective than alone, while crossflow mode improves the photocatalytic degradation performance of the system. GO integration in polymer membranes enhances their stability, facilitates photocatalytic processes, and gravity-driven GO membranes enable filtration of pollutants at low pressure, making membrane filtration more inexpensive. However, simultaneous removal of multiple contaminants with contrasting characteristics and variable efficiencies in different systems demands further optimization in GO-mediated membranes. This review concludes with identifying future critical research directions to promote research for determining the GO-assisted OMPs removal membrane technology nexus and maximizing this technique for industrial application.

Analysis of retinal cell development in chick embryo by immunohistochemistry and in ovo electroporation techniques.

BACKGROUND: Retinal cell development has been extensively investigated; however, the current knowledge of dynamic morphological and molecular changes is not yet complete. RESULTS: This study was aimed at revealing the dynamic morphological and molecular changes in retinal cell development during the embryonic stages using a new method of targeted retinal injection, in ovo electroporation, and immunohistochemistry techniques. A plasmid DNA that expresses the green fluorescent protein (GFP) as a marker was delivered into the sub-retinal space to transfect the chick retinal stem/progenitor cells at embryonic day 3 (E3) or E4 with the aid of pulses of electric current. The transfected retinal tissues were analyzed at various stages during chick development from near the start of neurogenesis at E4 to near the end of neurogenesis at E18. The expression of GFP allowed for clear visualization of cell morphologies and retinal laminar locations for the indication of retinal cell identity. Immunohistochemistry using cell type-specific markers (e.g., Visinin, Xap-1, Lim1+2, Pkcalpha, NeuN, Pax6, Brn3a, Vimentin, etc.) allowed further confirmation of retinal cell types. The composition of retinal cell types was then determined over time by counting the number of GFP-expressing cells observed with morphological characteristics specific to the various retinal cell types. CONCLUSION: The new method of retinal injection and electroporation at E3 - E4 allows the visualization of all retinal cell types, including the late-born neurons, e.g., bipolar cells at a level of single cells, which has been difficult with a conventional method with injection and electroporation at E1.5. Based on data collected from analyses of cell morphology, laminar locations in the retina, immunohistochemistry, and cell counts of GFP-expressing cells, the time-line and dynamic morphological and molecular changes of retinal cell development were determined. These data provide more complete information on retinal cell development, and they can serve as a reference for the investigations in normal retinal development and diseases.

Data for photoluminescence spectra of natural Cr3+-doped MgAl2O4 spinel during order-disorder transition.

Photoluminescence (PL) spectra of natural Cr3+ doped MgAl2O4 spinel from Tanzania were taken during its order-disorder transition (ODT) process. Samples were changed their disordered degree by quenching treatment. PL spectra were taken at the liquid nitrogen (LN) temperature (∼77 K) using a 532 nm laser excitation. Spectra from different states were compared with each other and R-line and N-line ratio was used to illustrate the disordered degree of spinel during ODT process. It can be used as a reference for other similar researches, such as spinel PL characterization of the other members of this group, ordered degree of synthetic spinel single crystal or ceramics materials, thermal history of spinel, and non-destructive identification of natural and heated spinel gemstones, spinel original distinguishing, further PL spectra analysis and XRD relationship research.

Standardized Attending Rounds to Improve the Patient Experience: A Pragmatic Cluster Randomized Controlled Trial.

BACKGROUND: At academic medical centers, attending rounds (AR) serve to coordinate patient care and educate trainees, yet variably involve patients. OBJECTIVE: To determine the impact of standardized bedside AR on patient satisfaction with rounds. DESIGN: Cluster randomized controlled trial. SETTING: 500-bed urban, quaternary care hospital. PATIENTS: 1200 patients admitted to the medicine service. INTERVENTION: Teams in the intervention arm received training to adhere to 5 AR practices: 1) pre-rounds huddle; 2) bedside rounds; 3) nurse integration; 4) real-time order entry; 5) whiteboard updates. Control arm teams continued usual rounding practices. MEASUREMENTS: Trained observers audited rounds to assess adherence to recommended AR practices and surveyed patients following AR. The primary outcome was patient satisfaction with AR. Secondary outcomes were perceived and actual AR duration, and attending and trainee satisfaction. RESULTS: We observed 241 (70.1%) and 264 (76.7%) AR in the intervention and control arms, respectively, which included 1855 and 1903 patient rounding encounters. Using a 5-point Likert scale, patients in the intervention arm reported increased satisfaction with AR (4.49 vs 4.25; P = 0.01) and felt more cared for by their medicine team (4.54 vs 4.36; P = 0.03). Although the intervention shortened the duration of AR by 8 minutes on average (143 vs 151 minutes; P = 0.052), trainees perceived intervention AR as lasting longer and reported lower satisfaction with intervention AR. CONCLUSIONS: Medicine teams can adopt a standardized, patient-centered, time-saving rounding model that leads to increased patient satisfaction with AR and the perception that patients are more cared for by their medicine team. Journal of Hospital Medicine 2017;12:143-149.

[Evidence of discontinuous property of water: study of infrared spectra at high temperature and high pressure].

The infrared spectra measurement for water has been conducted and investigated at the temperatures of 35-350 degrees C and the pressures of 1.7-2.7 GPa by using Hydrothermal Diamond Anvil Cell (HDAC). The result shows that the peak frequency and the full width at half height of the stretching vibration of water increases and decreases respectively with increasing pressure. It also shows that there is a discontinuousness at the pressure of 2. 1 GPa, that is, the frequency and the full width at half height of the peak have an obvious and discontinuous change from the pressures below and above 2.1 GPa, indicating that the property of water is discontinuous at high pressure. This is consistent with the discontinuous property of electrical conductivity from the previous studies for pure water and NaCl aqueous solution. Also it is consistent with the relationship between the temperature and the pressure of the dehydration of the bearing water minerals at about 2.0 GPa. It is expected that such a discontinuous property of water will play an important role on the minerals and rocks in the deep lithosphere and further detailed study needs to be done for them.

Time-of-flight mass spectrometry of mineral volatilization: toward direct composition analysis of shocked mineral vapor.

We have developed an orthogonal-acceleration time-of-flight mass spectrometer to study the volatiles produced when a mineral's shock-compressed state is isentropically released, as occurs when a shock wave, driven into the mineral by an impact, reflects upon reaching a free surface. The instrument is designed to use a gun or explosive-launched projectile as the source of the shock wave, impact onto a flange separating a poor vacuum and the high vacuum (10(-7) Torr) interior of the mass spectrometer, and transmission of the shock wave through the flange to a mineral sample mounted on the high-vacuum side of the flange. The device extracts and analyzes the neutrals and ions produced from the shocked mineral prior to the possible occurrence of collateral instrument damage from the shock-inducing impact. The instrument has been tested using laser ablation of various mineral surfaces, and the resulting spectra are presented. Mass spectra are compared with theoretical distributions of molecular species, and with expected distributions from laser desorption.