Journal of Biophotonics最新文献

Motor dysfunction of the upper limbs following a stroke predominantly arises from abnormal motor patterning caused by the disrupted balance of inter-cortical communication within motor-associated cortical regions. Temporal analysis offers a more precise reflection of the cortical functional state in affected patients. This study employed fNIRS to capture hemodynamic responses among 20 stroke patients and 19 healthy controls in both resting and Baduanjin task state. Including computing the coefficient of variation of fractional amplitude of low-frequency fluctuations (fALFF) for each channel, alongside extracting dynamic state metrics. Findings indicate that, during sustained motor tasks, stroke patients exhibit a diminished fALFF variability in targeted cortical regions; these individuals display a higher prevalence of low-intensity states and a lower prevalence of high-intensity states during task execution. These dynamic state attributes are significantly associated with scores on the upper limb motor function scale (FMA-UE), thereby proposing a time-domain perspective for investigating the underlying mechanisms of stroke-induced motor dysfunction.

Epicardial catheter ablation is necessary to address ventricular tachycardia targets located far from the endocardium, but epicardial adipose tissue and coronary blood vessels can complicate ablation. We demonstrate that catheter-based near-infrared spectroscopy (NIRS) can identify these obstacles to guide ablation. Eighteen human ventricles were mapped ex vivo using NIRS catheters with optical source-detector separations (SDSs) of 0.6 and 0.9 mm. A logistic regression model trained from manually labeled spectra achieved mean area under the receiver operating characteristic curve (AUROC) of 0.907 (0.6 mm SDS) and 0.911 (0.9 mm SDS) in binary adipose detection. Novel optical indices for adipose detection were also proposed, achieving AUROCs of 0.881 (0.6 mm SDS) and 0.873 (0.9 mm SDS), while a blood-specific optical index achieved AUROC of 0.859 for vessel detection (0.9 mm SDS). These results suggest that catheter-based NIRS can detect adipose tissue and coronary vessels to improve efficacy and safety of epicardial ablation.

The brain, as a vital part of central nervous system, receives approximately 25% of body's blood supply, making accurate monitoring of cerebral blood flow essential. While fNIRS is widely used for measuring brain physiology, complex tissue structure affects light intensity, spot size, and detection accuracy. Many studies rely on simulations with limited experimental validation. In this study, we used real adult skulls and agar to create a mimic model, building a transmission optical system with 13 wavelength filters and varying agar thicknesses. Peak intensity of transmitted light and size of scattered spot were measured at different wavelengths, and transmittance, total attenuation coefficient, and spot diameter enlargement of cranial mimics at different wavelengths were obtained. Results showed wavelengths below 550 nm struggled to penetrate the skull, while those above 700 nm penetrated deeper and diffused more. This suggests that short wavelengths capture epidermal PPG signals, whereas longer wavelengths detect both epidermal and intracranial signals.

Availability of a suitable tool for carrying out non-invasive measurement of Raman signatures in situ, from biological tissues having low Raman cross section is a clinically unmet need faced with manifold challenges. A Raman probe can prove to be an invaluable component of clinical Raman diagnostic systems. We present development of a Raman probe capable of measuring artefact free Raman spectra of biological tissues in situ. The developed probe uses a single lens for simultaneous illumination and collection of the Raman signal backscattered from the sample surface. This configuration ensures not only maximum overlapping of the illumination and collection volumes, ultimately leading to optimal throughput but also reduces the fiber-induced artefacts. The results show a superior performance of the developed Raman probe in measuring the Raman signatures from biological samples having lower Raman cross-sections, compared to that of the two commercially available Raman probes.

This study examines the effects of pulsed wave photobiomodulation (pwPBM) on the osteogenic differentiation of stem cells from the apical papilla (SCAP). Using 810 nm near-infrared (NIR) light with 300 Hz pulses and a 30% duty cycle, pwPBM was applied at a total energy density of 750 mJ/cm². Osteogenesis was evaluated through both in vitro and in vivo analyses. In vitro experiments demonstrated significant enhancement of alkaline phosphatase (ALP) activity, along with upregulation of key osteogenesis-related genes and proteins, as confirmed by real-time polymerase chain reaction (PCR) and Western blot analyses. In vivo, histological assessments following SCAP transplantation revealed increased bone tissue formation, further corroborated by osteocalcin staining. These findings underscore the potential of pwPBM as an innovative and effective tool for dental tissue regeneration and engineering.

Zerumbone is a sesquiterpene phytochemical with cytotoxic activity against cancer. This study aimed to evaluate the effect of zerumbone on cell viability by WST-1 test, apoptosis by TUNEL, lipid peroxidation markers (malondialdehyde, MDA, and 4-hydroxynonenal, HNE) by using assay kits, and biomolecular changes by ATR-FTIR spectroscopy in A549 cells. After zerumbone (0–100 μM) incubation for 24, 48, and 72 h, the number of TUNEL-positive cells was found to be higher in zerumbone-treated cells than in controls, in consistent with cell morphology results. MDA levels increased significantly, although HNE levels increased non-significantly in zerumbone-treated cells. Spectral analyses revealed that the zerumbone-treated groups had higher levels of total saturated and unsaturated lipids as well as comparatively shorter-chain lipids. On the contrary, reduced RNA/DNA ratio, total nucleic acid, and protein content were found in zerumbone-treated groups. Consequently, zerumbone-induced apoptosis was accompanied by increased aldehyde products during lipid peroxidation as well as biomolecular alterations.