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1.
Diabetes Metab Res Rev ; 40(4): e3813, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38767128

RESUMO

AIMS: The dawn phenomenon (DP) is an abnormal early morning blood glucose rise without nocturnal hypoglycaemia, which can be more easily and precisely assessed with continuous glucose monitoring (CGM). This prospective study aimed to explore the association between DP and the risk of all-cause mortality in patients with type 2 diabetes. MATERIALS AND METHODS: A total of 5542 adult inpatients with type 2 diabetes in a single centre were analysed. The magnitude of DP (ΔG) was defined as the increment in the CGM-determined glucose value from nocturnal nadir (after 24:00) to prebreakfast. Participants were stratified into four groups by ΔG: ≤1.11, 1.12-3.33, 3.34-5.55, and >5.55 mmol/L. Cox proportional hazard regression models were used to evaluate the impact of DP on all-cause mortality risk. RESULTS: During a median follow-up of 9.4 years, 1083 deaths were identified. The restricted cubic spline revealed a nonlinear (p for nonlinearity = 0.002) relationship between ΔG and the risk of all-cause mortality. A multivariate-adjusted Cox regression model including glycated haemoglobin A1c (HbA1c) showed that ΔG > 5.55 mmol/L was associated with 30% (95% CI, 1.01-1.66) higher risk of all-cause mortality, as compared with ΔG 1.12-3.33 mmol/L. CONCLUSIONS: Higher ΔG is significantly related to an increased risk of all-cause mortality in type 2 diabetes, suggesting that severe DP should be given more attention as a part of glucose management to reduce the risk of long-term adverse outcomes.


Assuntos
Glicemia , Diabetes Mellitus Tipo 2 , Humanos , Diabetes Mellitus Tipo 2/mortalidade , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/sangue , Feminino , Masculino , Pessoa de Meia-Idade , Glicemia/análise , Seguimentos , Estudos Prospectivos , Fatores de Risco , Prognóstico , Idoso , Hemoglobinas Glicadas/análise , Automonitorização da Glicemia , Causas de Morte , Biomarcadores/análise , Biomarcadores/sangue , Ritmo Circadiano/fisiologia , Hipoglicemia/mortalidade , Taxa de Sobrevida , Adulto
2.
Liver Int ; 2024 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-38842441

RESUMO

BACKGROUND: Glucosamine is a dietary supplement commonly used to support joint health. However, there has been interest in exploring other effects of glucosamine on health outcomes due to its ant-inflammation effect. OBJECTIVE: This study compared the risks of major adverse liver outcomes (MALOs) between regular users and non-users of glucosamine among patients with type 2 diabetes and metabolic dysfunction associated steatotic liver disease (MASLD) using the data from a large prospective cohort study. METHODS: Demographic, anthropometric, laboratory and medication prescription information among 18 753 patients with type 2 diabetes and MASLD was obtained from the UK Biobank. MASLD was identified based on hepatic steatosis defined by fatty liver index ≥60 plus the presence of any clues of metabolic dysregulation and cardio-metabolic risk factors, excluding patients with moderate to severe alcohol consumption. RESULTS: During a mean follow-up of 11.4 years, 826 incident MALOs events were recorded. Patients not regularly using glucosamine compared with patients using glucosamine showed a significantly higher risk of the composite MALOs (HR 1.36, 95% confidence interval [CI] 1.09-1.69) as well as most individual MALOs except for ascites. The multivariable-adjusted HRs of MALOs within 3, 5 and 10 years among non-users of glucosamine compared with regular users were 1.79 (95% CI .69-2.03), 1.88 (95% CI 1.21-2.54) and 1.32 (95% CI 1.05-1.72), respectively. Further subgroup analyses in participants with different baseline characteristics and sensitivity analyses excluding participants who regularly took any other supplements and participants who used self-reports to diagnose diabetes confirmed the findings. CONCLUSIONS: The present study indicated that habitual use of glucosamine was associated with a low risk of individual and composite MALOs among patients with type 2 diabetes and MASLD.

3.
J Am Chem Soc ; 145(4): 2183-2194, 2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36583711

RESUMO

The revival of ternary halides Li-M-X (M = Y, In, Zr, etc.; X = F, Cl, Br) as solid-state electrolytes (SSEs) shows promise in realizing practical solid-state batteries due to their direct compatibility toward high-voltage cathodes and favorable room-temperature ionic conductivities. Most of the reported superionic halide SSEs have a structural pattern of [MCl6]x- octahedra and generate a tetrahedron-assisted Li+ ion diffusion pathway. Here, we report a new class of zeolite-like halide frameworks, SmCl3, for example, in which 1-dimensional channels are enclosed by [SmCl9]6- tricapped trigonal prisms to provide a short jumping distance of 2.08 Å between two octahedra for Li+ ion hopping. The fast Li+ diffusion along the channels is verified through ab initio molecular dynamics simulations. Similar to zeolites, the SmCl3 framework can be grafted with halide species to obtain mobile ions without altering the base structure, achieving an ionic conductivity over 10-4 S cm-1 at 30 °C with LiCl as the adsorbent. Moreover, the universality of the interface-bonding behavior and ionic diffusion in a class of framework materials is demonstrated. It is suggested that the ionic conductivity of the MCl3/halide composite (M = La-Gd) is likely in correlation with the ionic conductivity of the grafted halide species, interfacial bonding, and framework composition/dimensions. This work reveals a potential class of halide structures for superionic conductors and opens up a new frontier for constructing zeolite-like frameworks in halide-based materials, which will promote the innovation of superionic conductor design and contribute to a broader selection of halide SSEs.

4.
Angew Chem Int Ed Engl ; 62(15): e202215544, 2023 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-36749663

RESUMO

The frustration in super-ionic conductors enables their exceptionally high ionic conductivities, which are desired for many technological applications including batteries and fuel cells. A key challenge in the study of frustration is the difficulties in analyzing a large number of disordered atomistic configurations. Using lithium super-ionic conductors as model systems, we propose and demonstrate the density of atomistic states (DOAS) analytics to quantitatively characterize the onset and degree of disordering, reveal the energetics of local disorder, and elucidate how the frustration enhances diffusion through the broadening and overlapping of the energy levels of atomistic states. Furthermore, material design strategies aided by the DOAS are devised and demonstrated for new super-ionic conductors. The DOAS is generally applicable analytics for unraveling fundamental mechanisms in complex atomistic systems and guiding material design.

5.
Chem Rev ; 120(13): 5954-6008, 2020 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-32347715

RESUMO

Ion transport in crystalline fast ionic conductors is a complex physical phenomenon. Certain ionic species (e.g., Ag+, Cu+, Li+, F-, O2-, H+) in a solid crystalline framework can move as fast as in liquids. This property, although only observed in a limited number of materials, is a key enabler for a broad range of technologies, including batteries, fuel cells, and sensors. However, the mechanisms of ion transport in the crystal lattice of fast ionic conductors are still not fully understood despite the substantial progress achieved in the last 40 years, partly because of the wide range of length and time scales involved in the complex migration processes of ions in solids. Without a comprehensive understanding of these ion transport mechanisms, the rational design of new fast ionic conductors is not possible. In this review, we cover classical and emerging characterization techniques (both experimental and computational) that can be used to investigate ion transport processes in bulk crystalline inorganic materials which exhibit predominant ion conduction (i.e., negligible electronic conductivity) with a primary focus on literature published after 2000 and critically assess their strengths and limitations. Together with an overview of recent understanding, we highlight the need for a combined experimental and computational approach to study ion transport in solids of desired time and length scales and for precise measurements of physical parameters related to ion transport.

6.
Chem Rev ; 120(10): 4257-4300, 2020 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-32271022

RESUMO

Solid-state batteries with desirable advantages, including high-energy density, wide temperature tolerance, and fewer safety-concerns, have been considered as a promising energy storage technology to replace organic liquid electrolyte-dominated Li-ion batteries. Solid-state electrolytes (SSEs) as the most critical component in solid-state batteries largely lead the future battery development. Among different types of solid-state electrolytes, garnet-type Li7La3Zr2O12 (LLZO) solid-state electrolytes have particularly high ionic conductivity (10-3 to 10-4 S/cm) and good chemical stability against Li metal, offering a great opportunity for solid-state Li-metal batteries. Since the discovery of garnet-type LLZO in 2007, there has been an increasing interest in the development of garnet-type solid-state electrolytes and all solid-state batteries. Garnet-type electrolyte has been considered one of the most promising and important solid-state electrolytes for batteries with potential benefits in energy density, electrochemical stability, high temperature stability, and safety. In this Review, we will survey recent development of garnet-type LLZO electrolytes with discussions of experimental studies and theoretical results in parallel, LLZO electrolyte synthesis strategies and modifications, stability of garnet solid electrolytes/electrodes, emerging nanostructure designs, degradation mechanisms and mitigations, and battery architectures and integrations. We will also provide a target-oriented research overview of garnet-type LLZO electrolyte and its application in various types of solid-state battery concepts (e.g., Li-ion, Li-S, and Li-air), and we will show opportunities and perspectives as guides for future development of solid electrolytes and solid-state batteries.

7.
Nano Lett ; 21(1): 151-157, 2021 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-33337887

RESUMO

Li phosphorus oxynitride (LiPON) is one of a very few solid electrolytes that have demonstrated high stability against Li metal and extended cyclability with high Coulombic efficiency for all solid-state batteries (ASSBs). However, theoretical calculations show that LiPON reacts with Li metal. Here, we utilize in situ electron microscopy to observe the dynamic evolutions at the LiPON-Li interface upon contacting and under biasing. We reveal that a thin interface layer (∼60 nm) develops at the LiPON-Li interface upon contact. This layer is composed of conductive binary compounds that show a unique spatial distribution that warrants an electrochemical stability of the interface, serving as an effective passivation layer. Our results explicate the excellent cyclability of LiPON and reconcile the existing debates regarding the stability of the LiPON-Li interface, demonstrating that, though glassy solid electrolytes may not have a perfect initial electrochemical window with Li metal, they may excel in future applications for ASSBs.

8.
Nano Lett ; 20(3): 1483-1490, 2020 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-31545613

RESUMO

All-solid-state lithium batteries (ASLBs) are promising for the next generation energy storage system with critical safety. Among various candidates, thiophosphate-based electrolytes have shown great promise because of their high ionic conductivity. However, the narrow operation voltage and poor compatibility with high voltage cathode materials impede their application in the development of high energy ASLBs. In this work, we studied the failure mechanism of Li6PS5Cl at high voltage through in situ Raman spectra and investigated the stability with high-voltage LiNi1/3Mn1/3Co1/3O2 (NMC) cathode. With a facile wet chemical approach, we coated a thin layer of amorphous Li0.35La0.5Sr0.05TiO3 (LLSTO) with 15-20 nm at the interface between NMC and Li6PS5Cl. We studied different coating parameters and optimized the coating thickness of the interface layers. Meanwhile, we studied the effect of NMC dimension to the ASLBs performance. We further conducted the first-principles thermodynamic calculations to understand the electrochemical stability between Li6PS5Cl and carbon, NMC, LLSTO, NMC/LLSTO. Attributed to the high stability of Li6PS5Cl with NMC/LLSTO and outstanding ionic conductivity of the LLSTO and Li6PS5Cl, at room temperature, the ASLBs exhibit outstanding capacity of 107 mAh g-1 and keep stable for 850 cycles with a high capacity retention of 91.5% at C/3 and voltage window 2.5-4.0 V (vs Li-In).

9.
Angew Chem Int Ed Engl ; 60(39): 21494-21501, 2021 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-34329513

RESUMO

All-solid-state battery with Li metal anode is a promising rechargeable battery technology with high energy density and improved safety. Currently, the application of Li metal anode is plagued by the failure at the interfaces between lithium metal and solid electrolyte (SE). However, little is known about the defects at Li-SE interfaces and their effects on Li cycling, impeding further improvement of Li metal anodes. Herein, by performing large-scale atomistic modeling of Li metal interfaces with common SEs, we discover that lithium metal forms an interfacial defect layer of nanometer-thin disordered lithium at the Li-SE interfaces. This interfacial defect Li layer is highly detrimental, leading to interfacial failure such as pore formation and contact loss during Li stripping. By systematically studying and comparing incoherent, coherent, and semi-coherent Li-SE interfaces, we find that the interface with good lattice coherence has reduced Li defects at the interface and has suppressed interfacial failure during Li cycling. Our finding discovered the critical roles of atomistic lithium defects at interfaces for the interfacial failure of Li metal anode, and motivates future atomistic-level interfacial engineering for Li metal anode in solid-state batteries.

10.
J Am Chem Soc ; 142(15): 7012-7022, 2020 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-32212650

RESUMO

The enabling of high energy density of all-solid-state lithium batteries (ASSLBs) requires the development of highly Li+-conductive solid-state electrolytes (SSEs) with good chemical and electrochemical stability. Recently, halide SSEs based on different material design principles have opened new opportunities for ASSLBs. Here, we discovered a series of LixScCl3+x SSEs (x = 2.5, 3, 3.5, and 4) based on the cubic close-packed anion sublattice with room-temperature ionic conductivities up to 3 × 10-3 S cm-1. Owing to the low eutectic temperature between LiCl and ScCl3, LixScCl3+x SSEs can be synthesized by a simple co-melting strategy. Preferred orientation is observed for all the samples. The influence of the value of x in LixScCl3+x on the structure and Li+ diffusivity were systematically explored. With increasing x value, higher Li+, lower vacancy concentration, and less blocking effects from Sc ions are achieved, enabling the ability to tune the Li+ migration. The electrochemical performance shows that Li3ScCl6 possesses a wide electrochemical window of 0.9-4.3 V vs Li+/Li, stable electrochemical plating/stripping of Li for over 2500 h, as well as good compatibility with LiCoO2. LiCoO2/Li3ScCl6/In ASSLB exhibits a reversible capacity of 104.5 mAh g-1 with good cycle life retention for 160 cycles. The observed changes in the ionic conductivity and tuning of the site occupations provide an additional approach toward the design of better SSEs.

11.
Inorg Chem ; 59(1): 226-234, 2020 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-31829567

RESUMO

Tremendous efforts have been devoted to the design of solid Li+ electrolytes and the development of all-solid-state batteries. Compared with conventional Li-ion batteries, which use flammable liquid organic electrolytes, all-solid-state batteries show significant advantages in safety. In this work, a novel lithium chlorothiophosphate compound, Li15P4S16Cl3, is discovered. The crystal structure and electrochemical properties are investigated. Li15P4S16Cl3 can be synthesized as a pure phase via a facile solid-state reaction by heating a ball-milled mixture of Li2S, P2S5, and LiCl at 360 °C. The crystal structure of Li15P4S16Cl3 was refined against neutron and synchrotron powder X-ray diffraction data, revealing that it crystallizes in the space group I4̅3d. The Li+ transport in Li15P4S16Cl3 was also investigated by multiple solid-state NMR methods, including variable-temperature NMR line-shape analysis, NMR relaxometry, and pulsed-field-gradient NMR. Li15P4S16Cl3 shows good thermodynamic stability and can be synthesized at relatively low temperature. Although it exhibits a low ionic conductivity at room temperature, it can serve as a new motif crystal structure for the design and development of new solid-state electrolytes.

12.
Angew Chem Int Ed Engl ; 59(40): 17472-17476, 2020 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-32597549

RESUMO

Sulfide solid electrolytes are promising inorganic solid electrolytes for all-solid-state batteries. Despite their high ionic conductivity and desirable mechanical properties, many known sulfide solid electrolytes exhibit poor air stability. The spontaneous hydrolysis reactions of sulfides with moisture in air lead to the release of toxic hydrogen sulfide and materials degradation, hindering large-scale manufacturing and applications of sulfide-based solid-state batteries. In this work, we systematically investigate the hydrolysis and reduction reactions in Li- and Na-containing sulfides and chlorides by applying thermodynamic analyses based on a first principles computation database. We reveal the stability trends among different chemistries and identify the effect of cations, anions, and Li/Na content on moisture stability. Our results identify promising materials systems to simultaneously achieve desirable moisture stability and electrochemical stability, and provide the design principles for the development of air-stable solid electrolytes.

13.
Angew Chem Int Ed Engl ; 58(24): 8039-8043, 2019 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-30977261

RESUMO

Enabling all-solid-state Li-ion batteries requires solid electrolytes with high Li ionic conductivity and good electrochemical stability. Following recent experimental reports of Li3 YCl6 and Li3 YBr6 as promising new solid electrolytes, we used first principles computation to investigate the Li-ion diffusion, electrochemical stability, and interface stability of chloride and bromide materials and elucidated the origin of their high ionic conductivities and good electrochemical stabilities. Chloride and bromide chemistries intrinsically exhibit low migration energy barriers, wide electrochemical windows, and are not constrained to previous design principles for sulfide and oxide Li-ion conductors, allowing for much greater freedom in structure, chemistry, composition, and Li sublattice for developing fast Li-ion conductors. Our study highlights chloride and bromide chemistries as a promising new research direction for solid electrolytes with high ionic conductivity and good stability.

14.
J Am Chem Soc ; 140(49): 17290-17296, 2018 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-30422649

RESUMO

Conventionally, phase diagrams serve as road maps for the design and synthesis of materials. However, bulk phase diagrams are often not as predictive for the synthesis of nanometric materials, mainly due to the increased significance of surface energy. The change of surface energy can drastically alter the total energy of the nanocrystals and thus yields a polymorph or metastable phase different from the stable phase in bulk, providing a means for controlling the synthesis of metastable phases. To achieve a theoretical and systematical understanding on the polymorphism of nanomaterials, metallic cobalt was chosen as a model system, where the two polymorphs, fcc and hcp phases, can be tuned with 100% selectivity in a solvothermal reaction. Advanced in situ synchrotron X-ray diffraction (XRD) technique and density functional theory (DFT) calculations were complementarily employed to reveal the size- and surface-dependent polymorphism at nanometer scale. The nanometric phase diagram provides a general predictive approach to guide the synthesis of metastable materials.

15.
Nat Mater ; 16(5): 572-579, 2017 05.
Artigo em Inglês | MEDLINE | ID: mdl-27992420

RESUMO

Garnet-type solid-state electrolytes have attracted extensive attention due to their high ionic conductivity, approaching 1 mS cm-1, excellent environmental stability, and wide electrochemical stability window, from lithium metal to ∼6 V. However, to date, there has been little success in the development of high-performance solid-state batteries using these exceptional materials, the major challenge being the high solid-solid interfacial impedance between the garnet electrolyte and electrode materials. In this work, we effectively address the large interfacial impedance between a lithium metal anode and the garnet electrolyte using ultrathin aluminium oxide (Al2O3) by atomic layer deposition. Li7La2.75Ca0.25Zr1.75Nb0.25O12 (LLCZN) is the garnet composition of choice in this work due to its reduced sintering temperature and increased lithium ion conductivity. A significant decrease of interfacial impedance, from 1,710 Ω cm2 to 1 Ω cm2, was observed at room temperature, effectively negating the lithium metal/garnet interfacial impedance. Experimental and computational results reveal that the oxide coating enables wetting of metallic lithium in contact with the garnet electrolyte surface and the lithiated-alumina interface allows effective lithium ion transport between the lithium metal anode and garnet electrolyte. We also demonstrate a working cell with a lithium metal anode, garnet electrolyte and a high-voltage cathode by applying the newly developed interface chemistry.

16.
J Am Chem Soc ; 138(37): 12258-62, 2016 09 21.
Artigo em Inglês | MEDLINE | ID: mdl-27570205

RESUMO

All-solid-state Li-batteries using solid-state electrolytes (SSEs) offer enhanced safety over conventional Li-ion batteries with organic liquid electrolytes due to the nonflammable nature of SSEs. The superior mechanical strength of SSEs can also protect against Li dendrite penetration, which enables the use of the highest specific capacity (3861 mAh/g) and lowest redox potential (-3.04 V vs standard hydrogen electrode) anode: Li metal. However, contact between the Li metal and SSEs presents a major challenge, where a large polarization occurs at the Li metal/SSE interface. Here, the chemical properties of a promising oxide-based SSE (garnet) changed from "super-lithiophobicity" to "super-lithiophilicity" through an ultrathin coating of amorphous Si deposited by plasma-enhanced chemical vapor deposition (PECVD). The wettability transition is due to the reaction between Li and Si and the in situ formation of lithiated Si. As a result, symmetric cells composed of a Si-coated garnet-structured SSE and Li metal electrodes exhibited much smaller impedance and excellent stability upon plating/stripping cycles compared to cells using bare garnet SSE. Specifically, the interfacial resistance between Li and garnet dramatically decreased from 925 to 127 Ω cm(2) when lithiated Si was formed on the garnet. Our discovery of switchable lithiophobic-lithiophilic surfaces to improve the Li metal/SSE interface opens opportunities for improving many other SSEs.

17.
Nat Mater ; 14(10): 1026-31, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26280225

RESUMO

Lithium solid electrolytes can potentially address two key limitations of the organic electrolytes used in today's lithium-ion batteries, namely, their flammability and limited electrochemical stability. However, achieving a Li(+) conductivity in the solid state comparable to existing liquid electrolytes (>1 mS cm(-1)) is particularly challenging. In this work, we reveal a fundamental relationship between anion packing and ionic transport in fast Li-conducting materials and expose the desirable structural attributes of good Li-ion conductors. We find that an underlying body-centred cubic-like anion framework, which allows direct Li hops between adjacent tetrahedral sites, is most desirable for achieving high ionic conductivity, and that indeed this anion arrangement is present in several known fast Li-conducting materials and other fast ion conductors. These findings provide important insight towards the understanding of ionic transport in Li-ion conductors and serve as design principles for future discovery and design of improved electrolytes for Li-ion batteries.

18.
Nano Lett ; 15(9): 5755-63, 2015 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-26288360

RESUMO

The development of sodium ion batteries (NIBs) can provide an alternative to lithium ion batteries (LIBs) for sustainable, low-cost energy storage. However, due to the larger size and higher m/e ratio of the sodium ion compared to lithium, sodiation reactions of candidate electrodes are expected to differ in significant ways from the corresponding lithium ones. In this work, we investigated the sodiation mechanism of a typical transition metal-oxide, NiO, through a set of correlated techniques, including electrochemical and synchrotron studies, real-time electron microscopy observation, and ab initio molecular dynamics (MD) simulations. We found that a crystalline Na2O reaction layer that was formed at the beginning of sodiation plays an important role in blocking the further transport of sodium ions. In addition, sodiation in NiO exhibits a "shrinking-core" mode that results from a layer-by-layer reaction, as identified by ab initio MD simulations. For lithiation, however, the formation of Li antisite defects significantly distorts the local NiO lattice that facilitates Li insertion, thus enhancing the overall reaction rate. These observations delineate the mechanistic difference between sodiation and lithiation in metal-oxide conversion materials. More importantly, our findings identify the importance of understanding the role of reaction layers on the functioning of electrodes and thus provide critical insights into further optimizing NIB materials through surface engineering.

19.
Diabetes Metab Res Rev ; 31(7): 725-33, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25952634

RESUMO

BACKGROUND: The aim of this study is to compare the efficacy and safety of once-daily insulin glargine plus gliclazide modified release combination therapy versus twice-daily premixed insulin monotherapy in Chinese type 2 diabetic patients insufficiently controlled by oral antidiabetic agents. METHODS: In a 12-week, multicenter, randomized, parallel-group clinical trial, patients with poor glycaemic control (fasting plasma glucose ≥ 7.0 mmol/L and 7.5% < haemoglobin A1c ≤ 10%) on oral antidiabetic drugs were randomized to the treatment groups for combination therapy (n = 52) or monotherapy (n = 53). Continuous glucose monitoring was carried out over two 72-h periods, at the beginning and the end of the study, and the data were used to calculate the 24-h mean blood glucose, mean amplitude of glycaemic excursions, standard deviation of blood glucose, and the mean of daily differences. RESULTS: The mean haemoglobin A1c decrease from baseline to study end was significant for both treatment groups (combination therapy: -1.23 ± 0.92%; insulin monotherapy: -1.02 ± 1.04%); moreover, the combination therapy group showed a significantly more robust haemoglobin A1c decrease (p = 0.0308). Both therapies significantly reduced the 24-h mean blood glucose (both, p < 0.001), but neither produced a significant effect on glycaemic variability, calculated as mean amplitude of glycaemic excursions, standard deviation of blood glucose, and mean of daily differences. In addition, the effects on rates of hypoglycaemic episodes were similar between the two therapies. CONCLUSIONS: Chinese patients with type 2 diabetes inadequately controlled with oral antidiabetic agents attained greater benefit from once-daily insulin glargine plus gliclazide modified release regimen than from a twice-daily premixed insulin regimen.


Assuntos
Glicemia/metabolismo , Diabetes Mellitus Tipo 2/tratamento farmacológico , Gliclazida/uso terapêutico , Hemoglobinas Glicadas/metabolismo , Hipoglicemiantes/uso terapêutico , Insulina Glargina/uso terapêutico , Automonitorização da Glicemia , China , Diabetes Mellitus Tipo 2/metabolismo , Quimioterapia Combinada , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Monitorização Ambulatorial , Resultado do Tratamento
20.
Phys Chem Chem Phys ; 17(27): 18035-44, 2015 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-26098541

RESUMO

We perform a first principles computational study of designing the Na0.5Bi0.5TiO3 (NBT) perovskite material to increase its oxygen ionic conductivity. In agreement with the previous experiments, our computation results confirm fast oxygen ionic diffusion and good stability of the NBT material. The oxygen diffusion mechanisms in this new material were systematically investigated, and the effects of local atomistic configurations and dopants on oxygen diffusion were revealed. Novel doping strategies focusing on the Na/Bi sublattice were predicted and demonstrated by the first principles calculations. In particular, the K doped NBT compound achieved good phase stability and an order of magnitude increase in oxygen ionic conductivity of up to 0.1 S cm(-1) at 900 K compared to the previous Mg doped compositions. This study demonstrated the advantages of first principles calculations in understanding the fundamental structure-property relationship and in accelerating the materials design of the ionic conductor materials.

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