Chronic Actinic Dermatitis (CAD) is an immune-mediated photodermatosis primarily affecting elderly males with prolonged sun exposure, though increasing reports highlight its occurrence in younger individuals, particularly those with darker skin types. CAD is characterized by pruritic eczematous lesions, lichenified papules, and plaques on sun-exposed areas, predominantly in response to ultraviolet (UV)B radiation, with some sensitivity to UVA and visible light. Concurrent photo contact allergies contribute to its pathogenesis. Despite well-established diagnostic criteria, clinical features remain crucial for diagnosis, with significant allergenic contact sensitivity observed in many cases. We report a case of a 48-year-old female with no significant medical history presenting with a longstanding, pruritic, painful rash localized to sun-exposed areas. Examination revealed eczematous patches and lichenification on the anterior neck, upper chest, forearms, and hands, involving approximately 25% of the body surface area. Her occupation as a manual labourer with significant sun exposure was a critical factor in disease onset. Photo testing confirmed heightened sensitivity to UVA and UVB radiation, leading to a diagnosis of CAD. The patient was managed with topical tacrolimus, stringent sun protection, and systemic therapy. Significant clinical improvement and sustained remission were achieved. Diagnosis of Chronic Actinic Dermatitis (CAD) relies heavily on clinical features and patient history. This case underscores the importance of occupational factors and sun exposure in CAD development. The patient’s presentation of hyperpigmented and erythematous plaques, along with depigmented lesions on the scalp, was successfully managed with corticosteroids, antihistamines, and sun protection strategies. This case highlights the significance of early recognition and tailored therapeutic approaches to achieve effective management of CAD. Bangladesh Journal of Infectious Diseases, December 2024;11(2):217-222

• Book : 11(2)
• Pub. Date : 2025
• Page : pp.217-222
• Keyword :

In the present study, temozolomide (TMZ), a drug used for the treatment of anaplastic astrocytoma and glioblastoma multiforme (GBM), was incorporated into multiwalled carbon nanotubes (MWCNTs) and a MWCNTs–graphene (MWCNTs-G) hybrid compound, covalently functionalized with polyethylene glycol (PEG) 6000 and folic acid (FA), with an aim to prepare nanocarriers with the potential to prolong the drug circulation time, cross the blood–brain–tumor barrier (BBTB), and provide targeted and controlled drug release in the brain tumor cells. Cytotoxicity and effects on cell membrane integrity of the blank and TMZ-loaded dual-functionalized carbon nanostructures (CNs) were evaluated in vitro on a GBM cell line (U87MG), as well as their radiosensitizing properties after exposure of the pre-treated GBM cells to gamma radiation with a standard clinical dose for patients with GBM. All prepared formulations underwent biopharmaceutical and physicochemical characterization, including the formulations exposed to irradiation under the same conditions. For physicochemical characterization of the formulations, different techniques were used by which successful functionalization of the CNs and TMZ loading were confirmed and visualized; no significant changes in the structure of the CNs and TMZ after irradiation were observed. With single and dual functionalization, formulations with relatively high TMZ loading efficiency and drug content were prepared. They exhibited homogeneous particle size distributions and mean particle sizes and surface charges suitable for crossing the BBTB and targeting brain cancer cells. A biphasic drug release profile was observed for all functionalized TMZ-loaded formulations in simulated in vivo conditions, with a sustained release pointing to the potential for controlled release of TMZ in brain tumor cells. The formulations of the hybrid CN MWCNTs-G compared to the corresponding MWCNTs were characterized by a similar or slightly higher TMZ content, larger particle size, similar surface charge, and slightly faster TMZ release, which can be attributed to the planar structure of graphene that promotes TMZ binding to the surface on a larger scale. For the irradiated CNs, lower values for particle size, more positive values for surface charge, and accelerated TMZ release were observed, which could be explained by changes in the physicochemical characteristics of the prepared formulations upon irradiation. Significant concentration-dependent toxicity was observed for blank dual-functionalized CNs, being higher for MWCNTs-G-PEG6000-FA compared to MWCNTs-PEG6000-FA at the same formulation concentrations. With incorporation of TMZ into the functionalized CNs, the cell viability additionally decreased, maintaining the trend for higher cytotoxicity of the hybrid CN. Additional decrease in the viability of cells was observed when GBM cells pre-treated with the corresponding CNs were exposed to irradiation, which could be ascribed to changes in size, surface charge, and release kinetics of TMZ and to irradiation-induced changes in the microenvironment and cell membranes that promote uptake of a larger volume of carriers in the GBM cells. The higher cytotoxicity observed in the hybrid carrier formulations could most likely be attributed to the length of the hybrid carrier and the higher proportion of planar surface, which promotes more intense contact with the cells and rupture of cell membranes. Overall, the findings demonstrate the radiosensitizing properties of not only TMZ but also of CNs and point to a clinical benefit from combined treatment with carbon nanocarriers of TMZ and radiotherapy in GBM.

• Book : 16()
• Pub. Date : 2025
• Page : pp.229-251
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Background/Objectives: Pyoderma gangrenosum (PG) is a rare neutrophilic dermatosis characterized by rapidly developing, painful ulcerative lesions. It exhibits pathergy, a phenomenon in which minor trauma or injury to the skin triggers an exaggerated inflammatory response. This leads to the development of new skin lesions or the worsening of existing ones. Treatment typically involves a combination of corticosteroids and immunosuppressive agents. However, even with effective therapy, the overall management of pyoderma gangrenosum remains challenging, and wound healing can be prolonged. The development of pyoderma gangrenosum after breast cancer surgery is rare, and its presence complicates the treatment of patients requiring additional oncologic therapy. In particular, the effect of radiation on these lesions is not well documented. Given the known skin toxicity of radiotherapy and its negative impact on wound healing, the use of adjuvant breast radiation raises significant concerns in this context. Methods: We present the case of a 66-year-old female with Stage IIB invasive ductal carcinoma of the left breast who developed postoperative pyoderma gangrenosum after breast-conserving surgery. The patient was treated with systemic corticosteroids and cyclosporine, and then subsequently underwent standard-of-care adjuvant chemotherapy and radiation. Results: During therapy, she demonstrated rapid resolution of her pyoderma gangrenosum without experiencing excess skin toxicity. Conclusions: While the literature on the direct application of radiation in pyoderma gangrenosum is limited, our case provides evidence supporting the safety of radiation therapy in oncologic cases complicated by this disease. In addition to receiving the benefit of adjuvant therapy for her breast cancer, our patient demonstrated an improvement in her postoperative PG with no adverse skin effects.

• Book : 14(4)
• Pub. Date : 2025
• Page : pp.1320-1320
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AbstractThe prediction of high‐energy radiation belt electrons is vital for preventing their damage to satellites. Previous machine learning models mostly predict the fluxes of high‐energy electrons (hundreds of keV to MeV) in the outer radiation belt and slot region (L > 2.6). Here, we trained a double‐layer long short‐term memory (LSTM) neural network model and successfully predicted the spatial and temporal variations of the 108–749 keV electrons in the inner radiation belt (L ∼ 1.2–2.2) and slot region (L ∼ 2.2–3.2). Under different solar or geomagnetic conditions, the prediction efficiency of the present model maintains 0.6–0.99 in the inner belt and slot region, and its prediction error is less than 0.48. The high‐resolution (∼11 s) LSTM model could predict the rapid injection events of high‐energy electrons within several minutes in the radiation belts.

• Book : 23(2)
• Pub. Date : 2025
• Page :
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The radiation physics of repeating fast radio bursts (FRBs) remains enigmatic. Motivated by the observed narrow-banded emission spectrum and ambiguous fringe pattern of the spectral peak frequency (ν_ pk) distribution of some repeating FRBs, such as FRB 20121102A, we propose that the bursts from repeating FRBs arise from synchrotron maser radiation in localized blobs within weakly magnetized plasma that relativistically moves toward observers. Assuming the plasma moves toward the observers with a bulk Lorentz factor of Γ=100 and the electron distribution in an individual blob is monoenergetic e ∼300), our analysis shows that bright and narrow-banded radio bursts with peak flux density ∼ 1 $ Jy $ at peak frequency (ν_ pk) ∼ 3.85 GHz can be produced by the synchrotron maser emission if the plasma blob has a magnetization factor of σ∼10^-5 and a frequency of P ∼ 4.5 MHz. The spectrum of bursts with lower ν_ pk tends to be narrower. Applying our model to the bursts of FRB 20121102A, the distributions of both the observed ν_ pk and isotropic energy E_ iso detected by the Arecibo telescope at the L band and the Green Bank Telescope at the C band are successfully reproduced. We find that the ν_ P distribution exhibits several peaks, similar to those observed in the ν_ pk distribution of FRB 20121102A. This implies that the synchrotron maser emission in FRB 20121102A is triggered in different plasma blobs with varying ν_ P, likely due to the inhomogeneity of relativistic electron number density.

• Book : ()
• Pub. Date : 2025
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AbstractEarly detection of emerging agricultural drought conditions is challenging but crucial for ensuring sustainable agriculture and global food security. Existing drought early warning systems utilize hydrometeorological or greenness‐based vegetation indicators. We propose that spaceborne measurements of solar‐induced chlorophyll fluorescence (SIF) yield (SIFyield), which is SIF normalized by absorbed photosynthetically active radiation (APAR), have the potential for early detection of emerging crop stress conditions. We evaluate meteorological (Standardized Precipitation Evapotranspiration Index (SPEI)), hydrological (root zone soil moisture (RZSM)), and physiological (SIF, and SIFyield) vegetation stress indicators to monitor the onset of crop stress indicated by reductions in gross primary productivity (GPP). Empirical Orthogonal Function and causal analysis indicate SIFyield has the strongest positive correlation with GPP, lagging by 1–2 months compared to other indicators. With its long lead time, space‐borne SIFyield can serve as an early indicator for agricultural drought onset, aiding global agricultural management efforts.

• Book : 52(4)
• Pub. Date : 2025
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Abstract Aim To evaluate a deep learning-based time-of-flight (DLToF) model trained to enhance the image quality of non-ToF PET images for different tracers, reconstructed using BSREM algorithm, towards ToF images. Methods A 3D residual U-NET model was trained using 8 different tracers (FDG: 75% and non-FDG: 25%) from 11 sites from US, Europe and Asia. A total of 309 training and 33 validation datasets scanned on GE Discovery MI (DMI) ToF scanners were used for development of DLToF models of three strengths: low (L), medium (M) and high (H). The training and validation pairs consisted of target ToF and input non-ToF BSREM reconstructions using site-preferred regularisation parameters (beta values). The contrast and noise properties of each model were defined by adjusting the beta value of target ToF images. A total of 60 DMI datasets, consisting of a set of 4 tracers (18F-FDG, 18F-PSMA, 68Ga-PSMA, 68Ga-DOTATATE) and 15 exams each, were collected for testing and quantitative analysis of the models based on standardized uptake value (SUV) in regions of interest (ROI) placed in lesions, lungs and liver. Each dataset includes 5 image series: ToF and non-ToF BSREM and three DLToF images. The image series (300 in total) were blind scored on a 5-point Likert score by 4 readers based on lesion detectability, diagnostic confidence, and image noise/quality. Results In lesion SUVmax quantification with respect to ToF BSREM, DLToF-H achieved the best results among the three models by reducing the non-ToF BSREM errors from -39% to -6% for 18F-FDG (38 lesions); from -42% to -7% for 18F-PSMA (35 lesions); from -34% to -4% for 68Ga-PSMA (23 lesions) and from -34% to -12% for 68Ga-DOTATATE (32 lesions). Quantification results in liver and lung also showed ToF-like performance of DLToF models. Clinical reader resulted showed that DLToF-H results in an improved lesion detectability on average for all four radiotracers whereas DLToF-L achieved the highest scores for image quality (noise level). The results of DLToF-M however showed that this model results in the best trade-off between lesion detection and noise level and hence achieved the highest score for diagnostic confidence on average for all radiotracers. Conclusion This study demonstrated that the DLToF models are suitable for both FDG and non-FDG tracers and could be utilized for digital BGO PET/CT scanners to provide an image quality and lesion detectability comparable and close to ToF.

• Book : ()
• Pub. Date : 2025
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Abstract A replacement of the three innermost layers of the new ALICE Inner Tracking System (ITS2), referred to as ITS3, is planned for the LHC Long Shutdown 3 (2026–2028) to further enhance tracking precision and efficiency. The ITS3 is designed as a cylindrically bent silicon vertex detector, utilizing stitched, wafer-scale sensors developed with the Tower Partners Semiconductor Co. 65 nm technology. The feasibility of this technology for ITS3 was evaluated using prototypes fabricated in the initial multi-reticle-layer run. This contribution presents the latest sensor characterization results from the analogue pixel test structures, focusing on detection efficiency, timing response, and radiation hardness.

• Book : 20(02)
• Pub. Date : 2025
• Page : pp.C02037-C02037
• Keyword :

Microbial communities in subsurface coastal sediments are highly diverse and play an important role in nutrient cycling. While the major fraction of microorganisms in sandy sediments lives as epipsammon (attached to sand grains), only a small fraction thrives in the interstitial porewaters. So far, little is known about the composition of these free-living microbial communities. In the subsurface of the sandy beach, investigated in this study, we compared the archaeal and bacterial community structures within sediments and corresponding porewaters applying 16S rRNA gene sequencing. We found that the free-living prokaryotes only had a proportion of about 0.2–2.3% of the bulk communities, depending on the pore space. The interstitial microbial communities showed a small overlap with the attached fraction of 4–7% ASVs, and comprised a unique composition of 75–81% ASVs found exclusively in the porewaters. They were more diverse than the respective sediment-attached fraction and showed a much higher archaea-to-bacteria ratio. The archaea were mainly affiliated to Nanoarchaeota of the DPANN superphylum, with a relative abundance up to 50% of the interstitial communities. The bacterial fraction included several species related to the Candidate Phyla Radiation (CPR). Both prokaryotic lineages are known to have small cell sizes, comprising not-yet cultured species with unidentified metabolic functions. Our findings were supported by the investigation of an adjacent tidal flat, showing a similar trend. Thus, our results indicate the presence of distinct interstitial microbial communities in the subsurface of coastal sediments. This natural enrichment of not-yet cultured Nanoarchaeota and members of the CPR provides the opportunity for targeted metagenomic analyses or even isolating members of these groups for further metabolic characterization.

• Book : ()
• Pub. Date : 2025
• Page :
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• Book : ()
• Pub. Date : 2025
• Page :
• Keyword :