Measuring the Ultrafast Correlation Dynamics of a Multilevel System Using the Center Line Slope Analysis in Two-Dimensional Electronic Spectroscopy.

In a two-dimensional (2D) optical spectrum of a multilevel system, there are diagonal peaks and off-diagonal cross-peaks that correlate the different levels. The time-dependent properties of these diagonal peaks and cross-peaks contain much information about the dynamics of the multilevel system. The time-dependent diagonal peakshape that depends on the spectral diffusion dynamics of the associated transition and characterized by the frequency-fluctuation correlation function (FFCF) is well studied. However, the time-dependent peakshape of a cross-peak that provides the correlation dynamics between different transitions is much less studied or understood. We derived the third-order nonlinear response functions that describe the cross-peaks in a 2D electronic spectrum of a multilevel system that arise from processes sharing a common ground state and/or from internal conversion and population transfer. We can use the center line slope (CLS) analysis to characterize the cross-peaks in conjunction with the diagonal peaks. This allows us to recover the frequency-fluctuation cross-correlation functions (FXCFs) between two transitions. The FXCF and its subsidiary quantities such as the initial correlation and the initial covariance between different transitions are important for studying the correlation effects between states in complex systems, such as energy-transfer processes. Furthermore, knowledge of how various molecular processes over different timescales affect simultaneously different transitions can also be obtained from the measured FXCF. We validated and tested our derived equations and analysis process by studying, as an example, the 2D electronic spectra of metal-free phthalocyanine in solution. We measured and analyzed the diagonal peaks of the Qx and Qy transitions and the cross-peaks between these two transitions of this multilevel electronic system and obtained the associated FFCFs and FXCFs. In this model system, we measured negative components of FXCF over the tens of picosecond timescale. This suggests that in phthalocyanine, the Qx and Qy transitions coupling with the solvent molecule motion are anticorrelated to each other.

Mitochondrial targeted antioxidants, mitoquinone and SKQ1, not vitamin C, mitigate doxorubicin-induced damage in H9c2 myoblast: pretreatment vs. co-treatment.

BACKGROUND: Preconditioning of the heart ameliorates doxorubicin (Dox)-induced cardiotoxicity. We tested whether pretreating cardiomyocytes by mitochondrial-targeted antioxidants, mitoquinone (MitoQ) or SKQ1, would provide better protection against Dox than co-treatment. METHODS: We investigated the dose-response relationship of MitoQ, SKQ1, and vitamin C on Dox-induced damage on H9c2 cardiomyoblasts when drugs were given concurrently with Dox (e.g., co-treatment) or 24 h prior to Dox (e.g., pretreatment). Moreover, their effects on intracellular and mitochondrial oxidative stress were evaluated by 2,7-dichlorofluorescin diacetate and MitoSOX, respectively. RESULTS: Dox (0.5-50 µM, n = 6) dose-dependently reduced cell viability. By contrast, co-treatment of MitoQ (0.05-10 µM, n = 6) and SKQ1 (0.05-10 µM, n = 6), but not vitamin C (1-2000 µM, n = 3), significantly improved cell viability only at intermediate doses (0.5-1 µM). MitoQ (1 µM) and SKQ1 (1 µM) significantly increased cell viability to 1.79 ± 0.12 and 1.59 ± 0.08 relative to Dox alone, respectively (both p < 0.05). Interestingly, when given as pretreatment, only higher doses of MitoQ (2.5 µM, n = 9) and SKQ1 (5 µM, n = 7) showed maximal protection and improved cell viability to 2.19 ± 0.13 and 1.65 ± 0.07 relative to Dox alone, respectively (both p < 0.01), which was better than that of co-treatment. Moreover, the protective effects were attributed to the significant reduction in Dox-induced intracellular and mitochondrial oxidative stress. CONCLUSION: The data suggest that MitoQ and SKQ1, but not vitamin C, mitigated DOX-induced damage. Moreover, MitoQ pretreatment showed significantly higher cardioprotection than its co-treatment and SKQ1, which may be due to its better antioxidant effects.

Biodegradation of wastewater in alternating aerobic-anoxic lab scale pilot plant by Alcaligenes sp. S3 isolated from agricultural field.

The isolated microbial Alcaligenes sp. S3 from the agricultural field was used for the biodegradation of synthetic wastewater containing atrazine. This study was conducted in an alternating aerobic-anoxic lab scale pilot plant. The performance of continuously operated pilot plant was evaluated in three different phases with varying atrazine concentration. The best performance of plant was observed in phase-II. The atrazine (200 mg/L) having COD value 1356 mg/L was used with varying flow rate and 90.56% COD removal was obtained at a flow rate of 300 mL/h on 122th day of operation. The effect of process parameter like pH and DO on the performance of the reactor was studied. The GC-MS analysis was investigated, and urea was found the intermediate/metabolites of atrazine biodegradation. The kinetic parameters such as half saturation rate constant (Ks) 106.80 mg/L; maximum specific growth rate (µmax) 0.208 per day and inhibition constant (Ki) 374.91 mg/L were evaluated by Andrew-Haldane model.

The value of dynamic contrast enhanced breast MRI in mammographically detected BI-RADS 5 microcalcifications.

AIMS: To evaluate the role of dynamic contrast-enhanced magnetic resonance imaging (MRI) in the diagnosis of BI-RADS-5 type of microcalcifications of the breast, to compare the size of the microcalcification lesions using mammography (MG) and MRI, and to determine the value of MRI in surgery for microcalcifications. The study also determines the morphology of microcalcification lesions, assesses kinetic curves and compare MRI features of ductal carcinoma in situ (DCIS) for different histopathological grades. METHODS: Our group consisted of 32 patients with mammographically detected BI-RADS 5 microcalcifications. The MRI was done in this group of women which was later followed by stereotactic vaccum-assisted biopsy (SVAB). Surgery was performed on all patients with a biopsy that resulted in a diagnosis of breast cancer or atypical ductal hyperplasia (ADH). RESULTS: Of our group of 32 patients, there were 35 mammograhically detected microcalcification lesions, 32 DCIS, one ADH and two benign findings according to the final histology. The microcalcification lesions were larger using MRI than in MG in 10 women. We diagnosed DCIS multifocality in 6 women and bilateral carcinoma in one woman. As with kinetic curve assessment, we found in 67 % of DCIS a rapid rise, 27 % a moderate and in 6 % a slow initial rise. With the pattern of enhancement in the delayed phase, we found in 30 % of DCIS a washout pattern, 67 % a plateau and in 3 % a persistent pattern. Noted difference between high and low grade DCIS was confirmed. CONCLUSIONS: MRI sensitivity in the detection of DCIS was 94 % in our group of patients and was the sole evidence for detection of multifocality and bilateral incidence of carcinoma. In 26 % of women the outcome of MRI was the most important for converting breast conserving surgery to mastectomy.

Pseudoangiomatous stromal hyperplasia of breast: a case report.

AIM: To present a case of pseudoangiomatous stromal hyperplasia (PASH) and its findings under 1. mammography - MG, 2. ultrasonography - USG and 3. magnetic resonance imaging - MRI. MATERIALS AND METHODS: A woman 39 years of age with a history of mass in her right breast of 3 months duration was subjected to a routine examination of the mass using MG & USG. According to the modality findings a core cut biopsy was done following which the samples were send for histological analysis. Later, MRI was done as advocated by the surgeon to get a better picture of the extent of the lesion prior to surgery. RESULTS: Bilateral mammogram views revealed in the patient's right breast a huge well-bordered tumour of lobulated contour without halo sign. Sonography revealed a big well-demarcated tumour in the central part of the right breast which was cystic and lobulated in shape. Histological analysis of the sample confirmed pseudoangiomatous stromal hyperplasia (PASH). MRI under a breast array coil revealed a mass of 85 x 75 x 35mm in the right breast. Finally, based on the clinical, radiological and histological report the mass was diagnosed as benign and despite the massive size of the mass, tumour excision alone was done and not mastectomy. The right breast after the huge tumour excision was almost normal in size compared to the left. CONCLUSION: PASH should be included in the differential diagnosis of a circumscribed or partially circumscribed mass, especially in the pre-menopausal female population. These benign masses often grow over time and can recur locally. Radiological diagnosis of PASH is usually done by MG and USG followed by core cut biopsy for histological analysis. However great the mass is, excision only of the tumor mass is recommended and not mastectomy.

Breast imaging using 3D electrical impedence tomography.

AIM: To determine the diagnostic efficiency of 3D Eletrical Impedance Tomography (EIT) compared to Mammography (MG) and Ultrasonography (USG) in imaging the breast. MATERIALS AND METHODS: A group of 88 patients presenting with various breast complaints was examined using combined Mammography and Ultrasonography (MG & USG) or either of these modalities alone. The same patients were then examined using the 3D EIT imaging system "MEIK". The findings were then compared. The sensitivity of these modalities for this group of patients were later determined and statistically analysed. RESULTS: Of the total of 88 patients, 59 findings were "suspicious" by any of the 3 modalities alone or by their combination. EIT had a sensitivity of 77.8 % compared to MG with a sensitivity of 83.3 % and USG with a sensitivity of 94.4 % regarding cases of fibrocystic mastitis. For cases involving cysts, EIT had 100 % sensitivity which was the same as that for USG compared to MG with a sensitivity of only 81 %. Among cases of fibroadenoma, EIT had a sensitivity of just 68.8 % compared to MG with a sensitivity of 87.5 % and USG with a sensitivity of 75 %. Finally among cases of carcinoma, EIT had a sensitivity of 75 % compared to the sensitivity of 100 % of MG and USG in our group of patients. The study revealed that there was no overall significant difference in sensitivity between MG-USG (p = 0.219) and MG-EIT (p = 0.779) and USG-EIT (p = 0.169). However, in regard to identifying cysts there was significant difference in the sensitivity of MG compared to USG & EIT suggesting that EIT has a role in these cases. CONCLUSION: Electrical impedance could be used as an adjunct to Mammography and Ultrasonography for breast cancer detection. However, the differentiation of malignant from benign lesions based on impedance measurements needs further investigation. Multifrequency electrical impedance imaging appears the most promising for detecting breast malignancies but methodological improvements need to be made to realise its potential.

The role of various modalities in breast imaging.

BACKGROUND: Breast cancer is the most common type of cancer in women worldwide. Mammography is considered the "gold standard" in the evaluation of the breast from an imaging perspective. Apart from mammography, ultrasound examination and magnetic resonance imaging are being offered as adjuncts to the preoperative workup. Recently, other new modalities like positron emission tomography, 99mTc-sestamibi scintimammography, and electrical impedance tomography (EIT) are also being offered. However, there is still controversy over the most appropriate use of these new modalities. Based on the literature, this review evaluates the role of various modalities used in the screening and diagnosis of breast cancer. METHODS AND RESULTS: Based on relevant literatures this article gives an overview of the old and new modalities used in the field of breast imaging. A narrative literature review of all the relevant papers known to the authors was conducted. The search of literatures was done using pubmed and ovid search engines. Additional references were found through bibliography reviews of relevant articles. It was clear that though various new technics and methods have emerged, none have substituted mammography and it is still the only proven screening method for the breast as of date. CONCLUSION: From the literature it is clear that apropos modern radiology's impact on diagnosis, staging and patient follow-up, only one imaging technique has had a significant impact on screening asymptomatic individuals for cancer i.e.; low-dose mammography. Mammography is the only screening test proven in breast imaging. Positron emission tomography (PET) also plays an important role in staging breast cancer and monitoring treatment response. As imaging techniques improve, the role of imaging will continue to evolve with the goal remaining a decrease in breast cancer morbidity and mortality. Progress in the development and commercialisation of EIT breast imaging system will definitely help to promote other systems and applications based on the EIT and similar visualization methods. Breast ultrasound and breast magnetic resonance imaging (MRI) are frequently used adjuncts to mammography in today's clinical practice and these techniques enhance the radiologist's ability to detect cancer and assess disease extent, which is crucial in treatment planning and staging.

A comparison of mammography and ultrasonography in the evaluation of breast masses.

AIM: Aim of the study is to evaluate breast masses using mammography (MG) and ultrasonography (USG) independently and in combination. MATERIALS AND METHODS: Our study group consisted of 62 female patients, with breast symptoms such as palpable lumps, pain in the breast and nipple discharge who were examined prospectively over a period of 6 months. All 62 patients were examined by both MG and USG independently. Fine needle aspiration cytology (FNAC) or core cut biopsy was done according to the findings of MG and USG and then the results were correlated with each modality finding. RESULTS: According to this study MG showed an efficiency of 81.8 % compared to 95.5 % for USG in detecting fibrocystic mastitis. However their combined approach resulted in 100 %. In the case of fibroadenomas, MG showed 75 % efficiency and USG only 35 % and the combination resulting in 93.7 %. For carcinomas, MG had an efficiency of 77.8 % and USG 55.6 %, but the combination had an efficiency of 98.1 %. Overall, the histopathological results when correlated with each modality finding showed that MG had an efficiency of only 77.4 % and USG only 69.8 % when used alone in detecting these lesions of the breast compared to an efficiency of 98.1 % obtained by their combined approach. In our study, we showed that there was no significant difference in sensitivity between MG and USG (p = 0.3768) but there was significant difference in MG alone and MG-USG combination (p = 0.0015) and USG alone and USG-MG combination (p = 0.0001). CONCLUSION: Our study confirmed that combined MG and USG had higher sensitivity rate than the sensitivity rate observed for either single modality. The diagnostic accuracy for carcinomas of the breast appear to improve when MG was combined with USG, even in cases which showed no evidence of microcalcification or other signs of abnormalities. Our study implies that, USG may be the only viable modality in pregnant and lactating women as it does not involve ionizing radiation and also in dense breast tissue, as density is a limiting factor for MG.