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1.
The diesel passenger car offers a substantial advantage in fuel economy over its gasoline-powered counterpart, but the long-range future of the diesel in this application is threatened by future federal standards on exhaust particular emissions. These particulates are primarily combustion-generated carbonaceous soot in combination with a solvent-extractable hydrocarbon fraction. Particulate production involves an incompletely understood series of phenomena that includes nucleation, surface growth, agglomeration, dehydrogenation, oxidation, and adsorption and condensation of gaseous hydrocarbons. The contemporary state of understanding of these events is reviewed as they apply to the passenger-car diesel engine.  相似文献   

2.
Breast cancer is the most prevalent cancer and the leading cause of cancer-related death among women worldwide. Type 2 diabetes–associated metabolic traits such as hyperglycemia, hyperinsulinemia, inflammation, oxidative stress, and obesity are well-known risk factors for breast cancer. The insulin sensitizer metformin, one of the most prescribed oral antidiabetic drugs, has been suggested to function as an antitumoral agent, based on epidemiological and retrospective clinical data as well as preclinical studies showing an antiproliferative effect in cultured breast cancer cells and animal models. These benefits provided a strong rationale to study the effects of metformin in routine clinical care of breast cancer patients. However, the initial enthusiasm was tempered after disappointing results in randomized controlled trials, particularly in the metastatic setting. Here, we revisit the current state of the art of metformin mechanisms of action, critically review past and current metformin-based clinical trials, and briefly discuss future perspectives on how to incorporate metformin into the oncologist’s armamentarium for the prevention and treatment of breast cancer.  相似文献   

3.
Breast and prostate cancers are frequently treated with chemotherapy. Several novel chemicals are being reported for this purpose, particularly synthetic and natural benzophenones. This work reports the synthesis of substituted 2-hydroxybenzophenones through 1,4-conjugate addition/intramolecular cycloaddition/dehydration of nitromethane on key intermediate chromones. Structures were extensively studied by means of 2D NMR spectroscopy and single-crystal XRD. Their cytotoxicity was evaluated in vitro in two breast cancer cell lines (MDA-MB-231 and T47-D) and one prostate cancer cell line (PC3). The most potent compound exhibited good cytotoxic effects against the three cancer cell lines (IC50 values ranging from 12.09 to 26.49 μm ) and induced cell-cycle retardation only on prostate cancer cells, which suggested that it might exert cell-type-specific effects.  相似文献   

4.
Severe asthma and rhinosinusitis represent frequent comorbidities, complicating the overall management of the disease. Both asthma and chronic rhinosinusitis (CRS) can be differentiated into endotypes: those with type 2 eosinophilic inflammation and those with a non-type 2 inflammation. A correct definition of phenotype/endotype for these diseases is crucial, taking into account the availability of novel biological therapies. Even though patients suffering from type 2 severe asthma—with or without CRS with nasal polyps—significantly benefit from treatment with biologics, the existence of different levels of patient response has been clearly demonstrated. In fact, in clinical practice, it is a common experience that patients reach a good clinical response for asthma symptoms, but not for CRS. At first glance, a reason for this could be that although asthma and CRS can coexist in the same patient, they can manifest with different degrees of severity; therefore, efficacy may not be equally achieved. Many questions regarding responders and nonresponders, predictors of response, and residual disease after blocking type 2 pathways are still unanswered. In this review, we discuss whether treatment with biological agents is equally effective in controlling both asthma and sinonasal symptoms in patients in which asthma and chronic rhinosinusitis with nasal polyps coexist.  相似文献   

5.
Cancer represents a large group of diseases accounting for nearly 10 million deaths each year. Various treatment strategies, including surgical resection combined with chemotherapy, radiotherapy, and immunotherapy, have been applied for cancer treatment. However, the outcomes remain largely unsatisfying. Melatonin, as an endogenous hormone, is associated with the circadian rhythm moderation. Many physiological functions of melatonin besides sleep–wake cycle control have been identified, such as antioxidant, immunomodulation, and anti-inflammation. In recent years, an increasing number of studies have described the anticancer effects of melatonin. This has drawn our attention to the potential usage of melatonin for cancer treatment in the clinical setting, although huge obstacles still exist before its wide clinical administration is accepted. The exact mechanisms behind its anticancer effects remain unclear, and the specific characters impede its in vivo investigation. In this review, we will summarize the latest advances in melatonin studies, including its chemical properties, the possible mechanisms for its anticancer effects, and the ongoing clinical trials. Importantly, challenges for the clinical application of melatonin will be discussed, accompanied with our perspectives on its future development. Finally, obstacles and perspectives of using melatonin for cancer treatment will be proposed. The present article will provide a comprehensive foundation for applying melatonin as a preventive and therapeutic agent for cancer treatment.  相似文献   

6.
Prostate cancer (CaP) is the most common type of tumour disease in men. Early diagnosis of cancer of the prostate is very important, because the sooner the cancer is detected, the better it is treated. According to that fact, there is great interest in the finding of new markers including amino acids, proteins or nucleic acids. Prostate specific antigen (PSA) is commonly used and is the most important biomarker of CaP. This marker can only be detected in blood and its sensitivity is approximately 80%. Moreover, early stages cannot be diagnosed using this protein. Currently, there does not exist a test for diagnosis of early stages of prostate cancer. This fact motivates us to find markers sensitive to the early stages of CaP, which are easily detected in body fluids including urine. A potential is therefore attributed to the non-protein amino acid sarcosine, which is generated by glycine-N-methyltransferase in its biochemical cycle. In this review, we summarize analytical methods for quantification of sarcosine as a CaP marker. Moreover, pathways of the connection of synthesis of sarcosine and CaP development are discussed.  相似文献   

7.
8.
Radiative properties of numerically generated fractal soot aggregates of different fractal dimensions were studied using the numerically accurate generalized Mie-solution method (GMM) and the Rayleigh-Debye-Gans (RDG) approximate theory. Fractal aggregates of identical prefactor but different fractal dimensions, namely, 1.4, 1.78, and 2.1, were generated numerically using a tunable algorithm of cluster–cluster aggregation for aggregates containing up to 800 primary particles. Radiative properties of these aggregates were calculated at a wavelength of 532 nm assuming a soot refractive index of 1.6 + 0.6i. Four commonly used structure factors in the RDG approximation were used to investigate the effect of structure factor on the differential and total scattering cross-sections and the asymmetry factor. The differential and total scattering properties calculated using the RDG approximation become increasingly sensitive to the structure factor with increasing the fractal dimension. Primary particle interactions are the fundamental mechanism for the aggregate absorption enhancement for small aggregates and the shielding effect for larger aggregates. The extent of these two competing factors is dependent on the fractal dimension and aggregate size. RDG reasonably predicts the effect of fractal dimension on the scattering properties, but fails to account for the effect of aggregation or fractal morphology on the absorption property of fractal soot aggregates, though the error is in general less than 15%.

Copyright 2013 American Association for Aerosol Research  相似文献   

9.
Metabolic changes during malignant transformation have been noted for many years in tumours. Otto Warburg first reported that cancer cells preferentially rely on glycolysis for energy production, even in the presence of oxygen, leading to the production of high levels of lactate. The crucial role of lactate efflux and exchange within the tumour microenvironment drew attention to monocarboxylate transporters (MCTs). MCTs have been recognized as promising targets in cancer therapy, and their expression was described in a large variety of tumours; however, studies showing how these isoforms contribute to the acquisition of the malignant phenotype are scarce and still unclear regarding prostate cancer. In this review, we focus on the role for MCTs in cell metabolism, supporting the development and progression of prostate cancer, and discuss the exploitation of the metabolic nature of prostate cancer for therapeutic and diagnostic purposes.  相似文献   

10.
11.
The structure and piezoelectricity of poly(vinylidene fluoride–trifluroethylene) copolymer doped with crystal violet (CV), Coumarin 2 (C2), and N,N-Dimethyl-4-nitro-4-stilbenamine (DANS) were investigated by several techniques. H- and J-aggregates are formed in the CV and C2 doped copolymer, respectively, while DANS doped copolymer showed lamella structure. Moreover, the application of pressure-induced crystalline phase in the CV doped copolymer and TSDC measurements revealed that the ferroelectric to paraelectric transition peak has taken place in the C2 and DANS doped copolymer. Kohlrausch-Williams-Watts stretched function was applied to estimate the relaxation time of the piezoelectric current. The pyroelectricity is found to be dipole-moment-dependent.  相似文献   

12.
Ischaemic stroke is a complex disease with some degree of heritability. This means that heritability factors, such as genetics, could be risk factors for ischaemic stroke. The era of genome-wide studies has revealed some of these heritable risk factors, although the data generated by these studies may also be useful in other disciplines. Analysis of these data can be used to understand the biological mechanisms associated with stroke risk and stroke outcome, to determine the causality between stroke and other diseases without the need for expensive clinical trials, or to find potential drug targets with higher success rates than other strategies. In this review we will discuss several of the most relevant studies regarding the genetics of ischaemic stroke and the potential use of the data generated.  相似文献   

13.
Androgen receptor targeted therapies for prostate cancer have serious limitations in advanced stages of the disease. While resistance to the FDA-approved enzalutamide is extensively documented, novel therapies based on epichlorohydrin scaffolds (EPI) are currently in clinical trials, but display suboptimal pharmacokinetics. Herein, we report the synthesis and biological characterisation of a novel class of compounds designed through covalently linking enzalutamide and EPI-001 through various triazole based linkers. The compounds display an 18 to 53 fold improvement in the cell killing potency towards C4-2b prostate cancer (PCa) cells compared to the gold standards of therapy, enzalutamide and EPI-001. The most promising compounds were proven to exhibit their toxicity exclusively through androgen receptor (AR) mediated pathways. This work sets the basis for the first class of hybrid AR inhibitors which successfully combine two drug moieties – EPI-001 and enzalutamide – into the same molecule.  相似文献   

14.
The structure and oxidation behaviors of pitch carbon,resin carbon and their mixture re-sultant carbon have been investigated.The results indicate that the pitch carbon has relative higher true specific gravity,well developed crystalline and better oxidation resistance than resin carbon,With 20%-35% resin added to pitch,the structure of the resultant carbon can be modified and oxidation resistance will be improved significantly.  相似文献   

15.
16.
A new girdle-like polyoxomolybdate was synthesized and characterized by single crystal X-ray diffraction. Study on its hollow central hole indicates that it is some kind of “inorganic crown ether” and can act as the host of some cations.  相似文献   

17.
Following several attempts to achieve a molecular stratification of bladder cancer (BC) over the last decade, a “consensus” classification has been recently developed to provide a common base for the molecular classification of bladder cancer (BC), encompassing a six-cluster scheme with distinct prognostic and predictive characteristics. In order to implement molecular subtyping (MS) as a risk stratification tool in routine practice, immunohistochemistry (IHC) has been explored as a readily accessible, relatively inexpensive, standardized surrogate method, achieving promising results in different clinical settings. The second part of this review deals with the pathological and clinical features of the molecular clusters, both in conventional and divergent urothelial carcinoma, with a focus on the role of IHC-based subtyping.  相似文献   

18.
Fundamentals and computer-aided methods of practice for the calculation and checking of azeotropes, and for the qualitative and rigorous determination of separating spaces for closed distillation are presented, which are valid for non-ideal multicomponent systems. Separating spaces can occur in azeotropic systems only and are decisive for the separability of a system, if distillation is the separation technique. As a prerequisite, a rigorous mathematical model of the vapour-liquid equilibrium is required. The eigenvalues and eigenvectors of the Jacobian matrix of the equilibrium concentrations are the key ingredients of several methods: the eigenvalues describe the asymptotic behaviour of closed distillation profiles, which indicates the order according to which components can be separated; the eigenvalues enter a topological equation for checking the thermodynamic consistency of the azeotropes of a system; the eigenvectors initiate paths connecting azeotropes and pure substances, from the network of which separating spaces can be deduced qualitatively; and eigenvectors are essential to initiate the rigorous profiles of separating spaces.  相似文献   

19.
Penile cancer is a rare tumor. There is a limited understanding of the biological mediators of prognostic and therapeutic importance in penile cancer. However, there exists some fundamental understanding of the major pathways involved in the development of penile pre-neoplastic lesions and neoplasms. The aim of the present review is to highlight our current state of molecular knowledge in penile cancer to foster the necessary tools for researchers to pave major advancements in our current treatment paradigms and cancer specific outcomes.  相似文献   

20.
Bladder cancer (BC) is a heterogeneous disease with highly variable clinical and pathological features, and resulting in different outcomes. Such heterogeneity ensues from distinct pathogenetic mechanisms and may consistently affect treatment responses in single patients. Thus, over the last few years, several groups have developed molecular classification schemes for BC, mainly based on their mRNA expression profiles. A “consensus” classification has recently been proposed to combine the published systems, agreeing on a six-cluster scheme with distinct prognostic and predictive features. In order to implement molecular subtyping as a risk-stratification tool in routine practice, immunohistochemistry (IHC) has been explored as a readily accessible, relatively inexpensive, standardized surrogate method, achieving promising results in different clinical settings. The first part of this review deals with the steps resulting in the development of a molecular subtyping of BC, its prognostic and predictive implications, and the main features of immunohistochemical markers used as surrogates to stratify BC into pre-defined molecular clusters.  相似文献   

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