Biomimetic Nanocomposites for Glioma Imaging and Therapy

Glioma, the most common primary brain tumor, is highly invasive and grows rapidly. As such, the survival of glioma patients is relatively short, highlighting the vital importance of timely diagnosis and treatment of glioma. However, the blood brain barrier (BBB) and the non-targeting delivery systems of contrast agents and drugs greatly hinder the effective glioma imaging and therapy. Fortunately, in recent years, investigators have constructed various biomimetic delivery platforms utilizing the exceptional advantages of biomimetic nanocomposites, such as immune evasion, homologous targeting ability, and BBB penetrating ability, to achieve efficient and precise delivery of substances to glioma sites for improved diagnosis and treatment. In this concept, we present the application of these biomimetic nanocomposites in fluorescence imaging (FI), magnetic resonance imaging (MRI), and multi-modal imaging, as well as in chemotherapy, phototherapy, and combined therapy for glioma. Lastly, we provide our perspective on this research field.

Biomimetic Nanocomposites Camouflaged with Hybrid Cell Membranes for Accurate Therapy of Early-Stage Glioma

Glioma features high fatality rate and short survival time of patients due to its fast growth speed and high invasiveness, hence timely treatment of early-stage glioma is extremely important. However, the blood brain barrier (BBB) severely prevents therapeutic agents from entering the brain; meanwhile, the non-targeted distribution of agents always causes side effects to vulnerable cerebral tissues. Therefore, delivery systems that possess both BBB penetrability and precise glioma targeting ability are keenly desired. We herein proposed a hybrid cell membrane (HM) camouflage strategy to construct therapeutic nanocomposites, in which HM consisting of brain metastatic breast cancer cell membrane and glioma cell membrane was prepared with a simple membrane fusion pathway. By coating HM onto drug-loaded nanoparticles, the as-obtained biomimetic therapeutic agent (termed HMGINPs) inherited satisfying BBB penetrability and homologous glioma targeting ability simultaneously from the two source cells. HMGINPs exhibited good biocompatibility and superior therapeutic efficacy towards early-stage glioma.

Meningitis Multiplex-PCR: 3-Year Study of Cost and Correlation With Traditional Cerebrospinal Fluid Analysis

Introduction/Objective

Physicians often rely on Cerebrospinal Fluid (CSF) cytology, chemistry, and culture. While cheap, these methods lack high sensitivity/specificity or have long turnaround times. PCR evaluation of CSF has become more common and is often touted as a way to save money, decrease turnaround times and quickly target antibiotics. PCR systems may cost $200,000, with $150 in disposables per test. As a new, fast, test it may be over ordered.

Methods/Case Report

Case-control study using retrospective chart review. All adults, aged 18 and over, who had undergone both PCR based testing and cytochemical testing between 3/1/2017 and 9/7/2019 were included.

Results (if a Case Study enter NA)

From 3/1/2017-9/7/2019, there were 381 available PCR results for adult GWUH patients. Demographic data showed that the patient sample was majority black (195/320, 60.94%), had an average age of 49.8 ± 17.2, and was majority female (172/320, 53.75%). The PCR results were 85.31% negative (273/320) and the CSF cultures were 94.38% negative. The most common PCR positive organism was Varicella zoster virus (11/47 positive results) and the most common CSF culture organism was Streptococcus pneumoniae (5/18 positive cultures).

Conclusion

In a population with clinical symptoms and at least 1 abnormality on CSF analysis, 6.5 tests were run for every positive PCR test. No single variable was found to significantly predict PCR results. Within a high initial cost, a disposable cost of $150 per test and detection rate of 14.7%, the cost to detect a single positive test by PCR could approach $4,500. PCR should be used judiciously following history, physical exam and standard CSF workup, rather than as a screening tool.

Brain Tumor Cell Membrane-Coated Lanthanide-Doped Nanoparticles for NIR-IIb Luminescence Imaging and Surgical Navigation of Glioma

Intraoperative visualization of the full extent of brain tumor by luminescence imaging helps to improve the degree and accuracy of brain tumor resection, thereby prolonging the survival of patients. However, the limited imaging depth and spatial resolution and the poor blood-brain barrier (BBB) permeability of most currently available luminescent probes restrict the imaging performance and surgical resection efficiency of brain tumor. Here, a brain tumor cell membrane-coated lanthanide-doped nanoparticles (CC-LnNPs) in the near-infrared-IIb window (NIR-IIb, 1500-1700 nm) is designed for brain tumor imaging and surgical navigation. The coating of brain tumor cell membrane endows CC-LnNPs with immune escape, BBB crossing, and homotypic targeting abilities, which are inherited from the source brain tumor cells. In addition, compared with clinically approved imaging agent indocyanine green, CC-LnNPs present higher temporal and spatial resolution, higher stability, and lower background signals, enabling clear visualization of the brain tumor boundary. With the guidance of NIR-IIb fluorescence, the glioma tissue (size < 3 mm, depth > 3 mm) could be clearly visualized and completely removed as a proof of concept. This study offers new insight for the future design of nanoprobe to image brain tumor and to achieve precise diagnosis and surgical navigation of brain tumor.

Loading Drugs in Natural Phospholipid Bilayers of Cell Membrane Shells to Construct Biomimetic Nanocomposites for Enhanced Tumor Therapy

Drug-based oncotherapy is seriously challenged by insufficient drug accumulation at tumor sites, mainly resulting from low drug loading efficiency and poor tumor-targeting ability of drug carriers. We herein proposed a "one-stone, two-bird" strategy to circumvent both obstacles, utilizing the source cancer cell membrane (CM) as a dual-function carrier to simultaneously achieve sufficient drug loading and homologous tumor targeting. Combining the use of TPGS (d-α-tocopherol polyethylene glycol 1000 succinate) to inhibit the drug efflux process of drug-resistant tumor, we constructed core-shell-structured nanocomposites CMGNPs consisting of ICG (indocyanine green)/DOX (doxorubicin)-loaded, TPGS/OA (oleic acid)-stabilized upconversion nanoparticles as the core and ICG-loaded MCF7/ADR CMs as the shell, for combined chemo/phototherapy of MCF7/ADR tumor. The employment of phospholipid bilayers of CMs as natural pockets for extra drug loading while preserving the homologous targeting ability greatly enhanced drug concentration at tumor sites, endowing CMGNPs with excellent therapeutic efficacy. Our effort provides a versatile approach for facilitating drug delivery in diverse therapeutic systems.

Gold nanoclusters as a GSH activated mitochondrial targeting photosensitizer for efficient treatment of malignant tumors

Gold nanoclusters (Au NCs), which have the characteristics of small size, near infrared (NIR) absorption and long triplet excited lifetime, have been used as a new type of photosensitizer for deep tissue photodynamic therapy (PDT). However, the therapeutic efficiency of the nano-system based on Au NCs still needs to be improved. Herein, we proposed a strategy using Mito-Au₂₅@MnO₂ nanocomposites to achieve enhanced PDT. Au₂₅(Capt)₁₈⁻ nanoclusters were applied as photosensitizers and further modified with peptides to target mitochondrial and MnO₂ nanosheets to consume glutathione (GSH). In the presence of GSH, Mito-Au₂₅@MnO₂ dis-integrated and Mito-Au₂₅ nanoparticles realized accurate mitochondrial targeting. Under the irradiation of 808 nm light, the nanocomposite ensured highly efficient PDT both in vitro and in vivo via oxidation pressure elevation and mitochondrial targeting in cancer cells.

This is the first example of mitochondrial targeting Au NCs capable of improving the efficiency of photodynamic therapy. Mito-Au₂₅@MnO₂ can be activated by consuming GSH and elevating oxidation pressure in cancer cells.

Sensitizing the Luminescence of Lanthanide-Doped Nanoparticles over 1500 nm for High-Contrast and Deep Imaging of Brain Injury

Real-time and in situ visualization of cerebrovascular dysfunction is significant for studying brain injury, which however, is restricted by the complex brain structure and limited imaging strategies. Luminescence imaging in NIR-IIb region (1500-1700 nm) is a promising tool owing to its merits including deep penetration, high resolution, and fast data acquisition. Unfortunately, a luminescent material in this region with sufficient brightness and biocompatibility is scarce. Herein, Ag₂Se quantum dot-sensitized lanthanide-doped nanocrystals (QDs-LnNCs) with emission beyond 1500 nm were fabricated to image the cerebrovascular structure and hemodynamics in ischemic stroke and traumatic brain injury. The sensitization by QDs provided an over 100-fold enhanced brightness of LnNCs and a remarkable penetration depth of 11 mm. Dynamic information of blood perfusion and flow rates were acquired and the damage of the blood-brain barrier in the two injury models was investigated. Our results proved QDs-LnNCs as a kind of competent nanomaterial for noninvasive brain imaging.

Extended anharmonic collapse of phonon dispersions in SnS and SnSe

The lattice dynamics and high-temperature structural transition in SnS and SnSe are investigated via inelastic neutron scattering, high-resolution Raman spectroscopy and anharmonic first-principles simulations. We uncover a spectacular, extreme softening and reconstruction of an entire manifold of low-energy acoustic and optic branches across a structural transition, reflecting strong directionality in bonding strength and anharmonicity. Further, our results solve a prior controversy by revealing the soft-mode mechanism of the phase transition that impacts thermal transport and thermoelectric efficiency. Our simulations of anharmonic phonon renormalization go beyond low-order perturbation theory and capture these striking effects, showing that the large phonon shifts directly affect the thermal conductivity by altering both the phonon scattering phase space and the group velocities. These results provide a detailed microscopic understanding of phase stability and thermal transport in technologically important materials, providing further insights on ways to control phonon propagation in thermoelectrics, photovoltaics, and other materials requiring thermal management.

Giant isotope effect on phonon dispersion and thermal conductivity in methylammonium lead iodide

Lead halide perovskites are strong candidates for high-performance low-cost photovoltaics, light emission, and detection applications. A hot-phonon bottleneck effect significantly extends the cooling time of hot charge carriers, which thermalize through carrier-optic phonon scattering, followed by optic phonon decay to acoustic phonons and finally thermal conduction. To understand these processes, we adjust the lattice dynamics independently of electronics by changing isotopes. We show that doubling the mass of hydrogen in methylammonium lead iodide by replacing protons with deuterons causes a large 20 to 50% softening of the longitudinal acoustic phonons near zone boundaries, reduces thermal conductivity by ~50%, and slows carrier relaxation kinetics. Phonon softening is attributed to anticrossing with the slowed libration modes of the deuterated molecules and the reduced thermal conductivity to lowered phonon velocities. Our results reveal how tuning the organic molecule dynamics enables control of phonons important to thermal conductivity and the hot-phonon bottleneck.

MR Imaging Correlates for Molecular and Mutational Analyses in Children with Diffuse Intrinsic Pontine Glioma

BACKGROUND AND PURPOSE

Recent advances in molecular techniques have characterized distinct subtypes of diffuse intrinsic pontine gliomas. Our aim was the identification of MR imaging correlates of these subtypes.

MATERIALS AND METHODS

Initial MRIs from subjects with diffuse intrinsic pontine gliomas recruited for a prospective clinical trial before treatment were analyzed. Retrospective imaging analyses included FLAIR/T2 tumor volume, tumor volume enhancing, the presence of cyst and/or necrosis, median, mean, mode, skewness, kurtosis of ADC tumor volume based on FLAIR, and enhancement at baseline. Molecular subgroups based on EGFR and MGMT mutations were established. Histone mutations were also determined (H3F3A, HIST1H3B, HIST1H3C). Univariate Cox proportional hazards regression was used to test the association of imaging predictors with overall and progression-free survival. Wilcoxon rank sum, Kruskal-Wallis, and Fisher exact tests were used to compare imaging measures among groups.

RESULTS

Fifty patients had biopsy and MR imaging. The median age at trial registration was 6 years (range, 3.3-17.5 years); 52% were female. On the basis of immunohistochemical results, 48 patients were assigned to 1 of 4 subgroups: 28 in MGMT-/epidermal growth factor receptor (EGFR)-, 14 in MGMT-/EGFR+, 3 in MGMT+/EGFR-, and 3 in MGMT+/EGFR+. Twenty-three patients had histone mutations in H3F3A, 8 in HIST1H3B, and 3 in HIST1H3C. Enhancing tumor volume was near-significantly different across molecular subgroups (P = .04), after accounting for the false discovery rate. Tumor volume enhancing, median, mode, skewness, and kurtosis ADC T2-FLAIR/T2 were significantly different (P ≤ .048) between patients with H3F3A and HIST1H3B/C mutations.

CONCLUSIONS

MR imaging features including enhancement and ADC histogram parameters are correlated with molecular subgroups and mutations in children with diffuse intrinsic pontine gliomas.

Upconversion System with Quantum Dots as Sensitizer: Improved Photoluminescence and PDT Efficiency

Upconversion nanoparticles (UCNPs) are prospective platforms for bioimaging and phototherapy, but a critical bottleneck is the limited brightness due to the faint absorptivity of lanthanide ions and the low quantum yield. To circumvent this problem, we herein propose our strategy to reconstruct the energy cascade of UCNPs using semiconductor quantum dots (QDs) as light sensitizer of Nd³⁺/Yb³⁺ codoped UCNPs. Ag₂Se QDs with strong absorption at 808 nm acted as efficient antenna and transferred their energy to Yb³⁺ via a resonance energy transfer process, significantly enhancing the luminescence of UCNPs. This nanocomposite was then combined with Rose Bengal and applied for photodynamic therapy. Both in vitro and in vivo studies revealed the introduction of QDs improved the therapeutic performance remarkably. Our study suggests Ag₂Se QDs with excellent photophysical properties can be promising agents to overcome the shortcomings of UCNPs and further strengthen their applications.

Spin-liquid-like state in pure and Mn-doped TbInO3 with a nearly triangular lattice

Inelastic neutron scattering studies in single crystals of TbInO3 and TbIn0.95Mn0.05O3 with nearly triangular antiferromagnetic lattice are reported. At low energies, a broad and apparently gapless continuum of magnetic excitations, located at the triangular lattice (TL) Brillouin zone boundary, is observed. The data are well described by the uncorrelated nearest-neighbor valence bonds model. At higher energies, a broad excitation branch dispersing from the TL zone boundary is observed. No signs of static magnetic order are found down to the temperatures two orders of magnitude smaller than the effective interaction energy. The fluctuating magnetic moment exceeds two-thirds of the Tb3+ free-ion value and is confined to the TL plane. These observations are consistent with a TL-based spin liquid state in TbInO3.

Construction of a two-photon fluorescent probe for ratiometric imaging of hypochlorous acid in alcohol-induced liver injury

A ratiometric two-photon fluorescent probe for HClO was deliberately constructed to reveal the generation of HClO in alcohol-induced liver injury.

Development of a red absorbing Se-rhodamine photosensitizer and its application for bio-orthogonally activatable photodynamic therapy

A π-extended Se-rhodamine was employed for the construction of a bio-orthogonally activatable photosensitizer.

Continuous nursing intervention on recovery of diabetic patients

The aim of this study was to probe the influence of continuous nursing intervention on recovery of diabetic patients. From October 2016 to June 2017, 80 diabetic patients who received treatment in our hospital were selected and randomly divided into an intervention group and a control group. The intervention group received continuous nursing care including indirect follow-up, health education and home visit. The self-care ability and blood sugar of the two groups were compared three months later. The score of self-care ability in the intervention group was 89.64±1.64 and that in control group was 72.68±2.47, and a significant difference was observed (P less than 0.001). The fasting blood glucose level in the intervention group was 6.62±0.86 MMOL/L, and the 2-hour post-meal blood glucose level was 8.47±1.32 MMOL/L, which were both lower than those in the control group. Continuous nursing can help monitor the recovery of patients after discharge. It is helpful to improve the self-care ability of patients, control blood sugar level, and promote recovery. It is worth wide promotion.

Influence of Spin-Orbit Coupling in Iron-Based Superconductors

We report on the influence of spin-orbit coupling (SOC) in Fe-based superconductors via application of circularly polarized spin and angle-resolved photoemission spectroscopy. We combine this technique in representative members of both the Fe-pnictides (LiFeAs) and Fe-chalcogenides (FeSe) with tight-binding calculations to establish an ubiquitous modification of the electronic structure in these materials imbued by SOC. At low energy, the influence of SOC is found to be concentrated on the hole pockets, where the largest superconducting gaps are typically found. This effect varies substantively with the k_{z} dispersion, and in FeSe we find SOC to be comparable to the energy scale of orbital order. These results contest descriptions of superconductivity in these materials in terms of pure spin-singlet eigenstates, raising questions regarding the possible pairing mechanisms and role of SOC therein.

Glassy Phonon Heralds a Strain Glass State in a Shape Memory Alloy

Shape memory strain glasses are frustrated ferroelastic materials with glasslike slow relaxation and nanodomains. It is possible to change a NiCoMnIn Heusler alloy from a martensitically transforming alloy to a nontransforming strain glass by annealing, but minimal differences are evident in the short- or long-range order above the transition temperature-although there is a structural relaxation and a 0.18% lattice expansion in the annealed sample. Using neutron scattering we find glasslike phonon damping in the strain glass but not the transforming alloy at temperatures well above the transition. Damping occurs in the mode with displacements matching the martensitic transformation. With support from first-principles calculations, we argue that the strain glass originates not with transformation strain pinning but with a disruption of the underlying electronic instability when disorder resonance states cross the Fermi level.

Supersonic propagation of lattice energy by phasons in fresnoite

Controlling the thermal energy of lattice vibrations separately from electrons is vital to many applications including electronic devices and thermoelectric energy conversion. To remove heat without shorting electrical connections, heat must be carried in the lattice of electrical insulators. Phonons are limited to the speed of sound, which, compared to the speed of electronic processes, puts a fundamental constraint on thermal management. Here we report a supersonic channel for the propagation of lattice energy in the technologically promising piezoelectric mineral fresnoite (Ba₂TiSi₂O₈) using neutron scattering. Lattice energy propagates 2.8−4.3 times the speed of sound in the form of phasons, which are caused by an incommensurate modulation in the flexible framework structure of fresnoite. The phasons enhance the thermal conductivity by 20% at room temperature and carry lattice-energy signals at speeds beyond the limits of phonons.

Fresnoite has an incommensurate structure that can be described as a nonlinear soliton lattice. Manley et al. show that the additional phason degrees of freedom associated with the solitonic structure can travel faster than more conventional phonon excitations, enabling supersonic energy transport.

Post hoc support vector machine learning for impedimetric biosensors based on weak protein–ligand interactions

We develop a simple, open source machine learning algorithm for analyzing impedimetric biosensor data using a mobile phone.

A two-photon fluorescent probe for nitroreductase imaging in living cells, tissues and zebrafish under hypoxia conditions

A two-photon fluorescent probe FNTR, constructed for nitroreductase by using a fluorine derivative as a TP fluorophore and a p-nitrobenzyl carbamate group as a recognition domain, was successfully applied to detect endogenous NTR in living cells, tissues and zebrafish.

Dispersing artifacts in FT-STS: a comparison of set point effects across acquisition modes

Fourier-transform scanning tunnelling spectroscopy (FT-STS), or quasiparticle interference, has become an influential tool for the study of a wide range of important materials in condensed matter physics. However, FT-STS in complex materials is often challenging to interpret, requiring significant theoretical input in many cases, making it crucial to understand potential artifacts of the measurement. Here, we compare the most common modes of acquiring FT-STS data and show through both experiment and simulations that artifact features can arise that depend on how the tip height is stabilized throughout the course of the measurement. The most dramatic effect occurs when a series of dI/dV maps at different energies are acquired with simultaneous constant current feedback; here a feature that disperses in energy appears that is not observed in other measurement modes. Such artifact features are similar to those arising from real physical processes in the sample and are susceptible to misinterpretation.

Application of Chitosan Films Enriched with Oregano Essential Oil on Bologna – Active Compounds and Sensory Attributes

Chitosan films prepared with oregano essential oil were applied on bologna slices. Release of the essential oil compounds during film preparation and application on the meat product and consumer acceptability of bologna enriched with oregano essential oil were tested. Oregano essential oil compounds were quantified by gas chromatography mass spectroscopy (GCMS) after extraction from the filmforming solution, films before and after application on bologna and from bologna slices before and after application of the films. The results indicated that the concentration of components of the essential oil sharply decreased during film preparation, e.g. from 757.7 ppm carvacrol in film-forming solution to 2.1 ppm in dried films. No carvacrol was detected in the films after application on bologna for 5 days at 4°C, mainly due to its diffusion into bologna. It seemed that the moisture and high lipid content of bologna helped the diffusion of the oregano essential oil from the chitosan film matrix into the product. Sensory evaluation suggested that addition of 45 ppm or less of oregano oil to bologna would be acceptable to consumers. Results support the potential use of chitosan–oregano essential oil films as an antimicrobial packaging material for processed meat.

Thermal Conductivity of the Iron-Based Superconductor FeSe: Nodeless Gap with a Strong Two-Band Character

The thermal conductivity κ of the iron-based superconductor FeSe was measured at temperatures down to 75 mK in magnetic fields up to 17 T. In a zero magnetic field, the electronic residual linear term in the T=0  K limit, κ_{0}/T, is vanishingly small. The application of a magnetic field B causes an exponential increase in κ_{0}/T initially. Those two observations show that there are no zero-energy quasiparticles that carry heat and therefore no nodes in the superconducting gap of FeSe. The full field dependence of κ_{0}/T has the classic two-step shape of a two-band superconductor: a first rise at very low field, with a characteristic field B^{⋆}≪B_{c2}, and then a second rise up to the upper critical field B_{c2}. This shows that the superconducting gap is very small (but finite) on one of the pockets in the Fermi surface of FeSe. We estimate that the minimum value of the gap, Δ_{min}, is an order of magnitude smaller than the maximum value, Δ_{max}.

The unusual magnetism of nanoparticle LaCoO3

Bulk and nanoparticle powders of LaCoO3 (LCO) were synthesized and their magnetic and structural properties were studied using SQUID magnetometry and neutron diffraction. The bulk and large nanoparticles exhibit weak ferromagnetism (FM) below T ≈ 85 K and a crossover from strong to weak antiferromagnetic (AFM) correlations near a transition expressed in the lattice parameters, To≈40 K. This crossover does not occur in the smallest nanoparticles; instead, the magnetic behavior is predominantly ferromagnetic. The amount of FM in the nanoparticles depends on the amount of Co3O4 impurity phase, which induces tensile strain on the LCO lattice. A core-interface model is introduced, with the core region exhibiting the AFM crossover and with FM in the interface region near surfaces and impurity phases.

Spin-chirality-driven ferroelectricity on a perfect triangular lattice antiferromagnet

Magnetic field (B) variation of the electrical polarization P(c) (∥c) of the perfect triangular lattice antiferromagnet RbFe(MoO(4))(2) is examined up to the saturation point of the magnetization for B⊥c. P(c) is observed only in phases for which chirality is predicted in the in-plane magnetic structures. No strong anomaly is observed in P(c) at the field at which the spin modulation along the c axis, and hence the spin helicity, exhibits a discontinuity to the commensurate state. These results indicate that the ferroelectricity in this compound originates predominantly from the spin chirality, the explanation of which would require a new mechanism for magnetoferroelectricity. The obtained field-temperature phase diagram of ferroelectricity agree well with those theoretically predicted for the spin chirality of a Heisenberg spin triangular lattice antiferromagnet.

Development of a compact in situ polarized ³He neutron spin filter at Oak Ridge National Laboratory

We constructed a compact in situ polarized (3)He neutron spin filter based on spin-exchange optical pumping which is capable of continuous pumping of the (3)He gas while the system is in place in the neutron beam on an instrument. The compact size and light weight of the system simplifies its utilization on various neutron instruments. The system has been successfully tested as a neutron polarizer on the triple-axis spectrometer (HB3) and the hybrid spectrometer (HYSPEC) at Oak Ridge National Laboratory. Over 70% (3)He polarization was achieved and maintained during the test experiments. Over 90% neutron polarization and an average of 25% transmission for neutrons of 14.7 meV and 15 meV was also obtained.

The impact of the International Association of Diabetes and Pregnancy Study Groups (IADPSG) fasting glucose diagnostic criterion on the prevalence and outcomes of gestational diabetes mellitus in Han Chinese women

AIMS

The International Association of Diabetes and Pregnancy Study Groups (IADPSG) proposed that a one-time value of fasting plasma glucose of 5.1 mmol/l or over at any time of the pregnancy is sufficient to diagnose gestational diabetes. We evaluated the repercussions of the application of this threshold in pregnant Han Chinese women.

METHODS

This is a retrospective study of 5360 (72.3% of total) consecutively recruited pregnant Han Chinese women in one centre from 2008 to 2011. These women underwent a two-step gestational diabetes diagnostic protocol according to the previous American Diabetes Association criteria. The IADPSG fasting plasma glucose criterion was used to reclassify these 5360 women. The prevalence, clinical characteristics and obstetric outcomes were compared among the women classified as having gestational diabetes by the previous American Diabetes Association criteria (approximately 90% were treated), those reclassified as having gestational diabetes by the single IADPSG fasting plasma glucose criterion (untreated), but not as having gestational diabetes by the previous American Diabetes Association criteria, and those with normal glucose tolerance.

RESULTS

There were 626 cases of gestational diabetes defined by the previous American Diabetes Association criteria (11.7%) and these cases were associated with increased risks of maternal and neonatal outcomes when compared with the women with normal glucose tolerance. With the IADPSG fasting plasma glucose criterion, another 1314 (24.5%) women were reclassified as having gestational diabetes. Gestational diabetes classified by the IADPSG fasting plasma glucose criterion was associated with gestational hypertension (P = 0.0094) and neonatal admission to nursery (P = 0.035) prior to adjustment for maternal age and BMI, but was no longer a predictor for adverse pregnancy outcomes after adjustment.

CONCLUSION

The simple IADPSG fasting plasma glucose criterion increased the Chinese population with gestational diabetes by 200%. The increased population with gestational diabetes was not significantly associated with excess obstetric and neonatal morbidity.

Polar and magnetic layered A-site and rock salt B-site-ordered NaLnFeWO6 (Ln = La, Nd) perovskites

We have expanded the double perovskite family of materials with the unusual combination of layered order in the A sublattice and rock salt order over the B sublattice to compounds NaLaFeWO6 and NaNdFeWO6. The materials have been synthesized and studied by powder X-ray diffraction, neutron diffraction, electron diffraction, magnetic measurements, X-ray absorption spectroscopy, dielectric measurements, and second harmonic generation. At room temperature, the crystal structures of both compounds can be defined in the noncentrosymmetric monoclinic P2(1) space group resulting from the combination of ordering both in the A and B sublattices, the distortion of the cell due to tilting of the octahedra, and the displacement of certain cations. The magnetic studies show that both compounds are ordered antiferromagnetically below T(N) ≈ 25 K for NaLaFeWO6 and at ∼21 K for NaNdFeWO6. The magnetic structure of NaNdFeWO6 has been solved with a propagation vector k = ((1/2) 0 (1/2)) as an antiferromagnetic arrangement of Fe and Nd moments. Although the samples are potential multiferroics, the dielectric measurements do not show a ferroelectric response.

Magnetism and phase transitions in LaCoO3

Neutron scattering and magnetometry measurements have been used to study phase transitions in LaCoO3 (LCO). For H ≤ 100 Oe, evidence for a ferromagnetic (FM) transition is observed at Tc ≈ 87 K. For 1 kOe ≤ H ≤ 60 kOe, no transition is apparent. For all H, Curie-Weiss analysis shows predominantly antiferromagnetic (AFM) interactions for T > Tc, but the lack of long-range AFM order indicates magnetic frustration. We argue that the weak ferromagnetism in bulk LCO is induced by lattice strain, as is the case with thin films and nanoparticles. The lattice strain is present at the bulk surfaces and at the interfaces between the LCO and a trace cobalt oxide phase. The ferromagnetic ordering in the LCO bulk is strongly affected by the Co-O-Co angle (γ), in agreement with recent band calculations which predict that ferromagnetic long-range order can only take place above a critical value, γC. Consistent with recent thin film estimations, we find γC = 162.8°. For γ > γC, we observe power-law behavior in the structural parameters. γ decreases with T until the critical temperature, To ≈ 37 K; below To the rate of change becomes very small. For T < To, FM order appears to be confined to regions close to the surfaces, likely due to the lattice strain keeping the local Co-O-Co angle above γC.

Molecular cloning and characterization of an endogenous digestive β-glucosidase from the midgut of the fungus-growing termite Macrotermes barneyi

β-glucosidase from the midgut of the fungus-growing termite Macrotermes barneyi was first cloned and characterized to gain a better understanding of cellulolytic systems in fungus-growing termites. β-glucosidase activity was proven to present primarily in the midgut of M. barneyi and two β-glucosidases were partially purified from the midgut. Based on the N-terminus sequence of one of the β-glucosidases, a full-length cDNA fragment of 1708 bp was obtained. This sequence encodes a 493 amino acid protein belonging to glycoside hydrolase family 1. Quantitative real-time PCR analysis proved that the β-glucosidase gene was primarily expressed in the midgut. β-glucosidase was expressed heterologously and biochemically characterized. Results indicate that β-glucosidase is an endogenous, midgut-origin termite digestive enzyme. It may have applications in understanding the mechanism of lignocellulose degradation in fungus-growing termites.

Individual differences in locomotor activity are associated with levels of tyrosine hydroxylase and neurofilament proteins in the ventral tegmental area of sprague-dawley rats

We have demonstrated previously that chronic morphine and cocaine treatments increase levels of tyrosine hydroxylase (TH), and decrease levels of neurofilament (NF) proteins, in the ventral tegmental area (VTA), a major dopaminergic brain reward region, of outbred Sprague-Dawley rats. We have also found inherent differences in levels of these proteins in the VTA of inbred rat strains that differ in their behavioral responses to opiates, cocaine, and other drugs of abuse, with the Lewis rat showing higher levels of TH and lower levels of NFs in the VTA compared to the Fischer 344 rat. Based on recent reports that individual differences in drug responses among outbred Sprague-Dawley rats are highly correlated with the animals' locomotor response to novelty, we determined in the present study whether such within-strain differences in locomotor behavior are also associated with differences in levels of TH and NFs in the VTA. Groups of 42 Sprague-Dawley rats were assessed for locomotor activity in a novel environment. The four animals from each group with the lowest locomotor responses (designated L rats), and the four with the highest locomotor responses (designated H rats), were analyzed for TH and NF immunoreactivity by immunoblotting procedures. It was found that the VTA of L rats exhibited higher levels of TH and lower levels of three major NF proteins, NF-200, NF-160, and NF-68, compared to the VTA of H rats. A tendency for similar L versus H differences in TH and NF levels were observed when groups of rats with the second lowest and second highest locomotor responses were compared; no differences were seen in groups whose locomotor responses were closer to the median. These biochemical differences between H and L rats showed regional specificity, with no significant differences seen in several other regions of brain or spinal cord studied. Differences were also observed between L and H rats in their locomotor responses to acute and repeated cocaine exposure. The possible relationship between the individual differences in TH and NFs and individual differences in locomotor activity and other drug-related behaviors is discussed.