In the vibrational spectra of biological molecules, indelible “fingerprints” can be found for the occurrence (and frequency) of a number of otherwise hidden natural phenomena. The discovery and rationalization of such spectral “fingerprints” represents a socially useful and fascinating practice, but also pose formidable challenges to spectroscopists. Unlike simpler inorganic structures, an explicit description of the irreducible phonon representation for complicated organic molecules is a task of enormous cumbersomeness, which can by no means be accomplished without the help of computational programs. Even an “elementary” protein structure possesses a number of distinct vibrational modes (i.e., in the order of ${10}^4$),¹ which makes the task of unfolding such a structural complexity one of the hardest challenges in modern science. On the positive side, however, there is the high sensitivity of vibrational spectroscopy to structural features. This method can be exceptionally sensitive to even quite small variations of bond strength, i.e., in the order of 0.02%.² Such variations can promptly be resolved by probing with a spectral resolution better than $5{\mathrm{cm}}^{-1}$, and modern spectroscopes usually possess spectral resolutions at least 1 order of magnitude better than the above threshold. In other words, Raman spectroscopy provides us with a suitably high sensitivity for monitoring subtle bond modifications and molecular distortions with high accuracy.

Despite advancements in medical technology, the challenges of diagnosing fever of unknown origin (FUO) and inflammation of unknown origin (IUO) persist. Positron emission tomography/computed tomography (PET/CT) has been used to assess these conditions; however, it is unclear which patients most benefit from this approach. This study aimed to assess the clinical value and optimal use of fluorine-18-labelled-fluorodeoxyglucose (¹⁸F-FDG)-PET/CT in patients with FUO/IUO. We reviewed FDG-PET/CT scans conducted at our department between January 2014 and December 2020 to further assess FUO/IUO. FUO was defined as a fever lasting over three weeks without a diagnosis based on conventional assessment. IUO was defined as prolonged inflammation with a body temperature below 38.3 ℃ and without a diagnosis after conventional diagnostic procedures. The efficacy of FDG-PET/CT was determined based on the diagnostic outcomes achieved by integrating imaging findings with histopathological or microbiological evidence, clinical criteria, or follow-up assessments. We conducted crude and age-sex adjusted logistic regression for potential risk factors to determine the degree of burden on demographic and clinical characteristics. Forty-five patients with FUO/IUO underwent FDG-PET/CT, and final diagnoses were made in 32 patients (71.1%). The percentages of diagnostic categories were 53.3%, 8.9%, and 6.7% for non-infectious inflammatory diseases, malignancy, and infection, respectively. In multivariable logistic regression analysis, IUO was the only independent predictor of the efficacy of FDG-PET/CT in the final diagnosis (odds ratio, 67.02; 95% confidence interval, 4.02–1119). Our results indicate that IUO was associated with a higher diagnostic yield compared to those with FUO.

Background: After the confirmation of coronavirus infection in Japan, a behavioral change caused people and physicians to refrain from visiting hospitals or undergoing examinations. This study aimed to assess how the trend of diagnosis in gastric cancers changed, and how it affected the therapeutic strategies and the interval from diagnosis to treatment during the COVID‐19 pandemic.Methods: We use 15 cancer‐designated hospitals’ registries in Hiroshima, Japan. The target period was March to December 2020, and the same period in 2019 was set as the control period. The monthly mean of diagnoses and the interval from diagnosis to treatment were compared overall and separately by age, treatment procedure, diagnostic process, and clinical stage.Result: In 2020, the monthly mean (standard deviation [SD]) of patients was 192.2 (29.9), a significant 20.1% decrease from 240.7 (20.7) in 2019 due to older age and curative treatment groups. By reason for performing endoscopy, the change rate in cancer screening, endoscopic follow‐up, and symptomatic status were ‐27.0%, ‐18.0%, and ‐17.3%, respectively. Meanwhile, the interval (days) from diagnosis to treatment (SD) was 37.8 (26.5) in 2020, significantly shorter than 46 (31.5) in 2019.Conclusion: From 2019 to 2020, we observed a significant decrease in the diagnosis of curable early‐stage gastric cancer and treatments, although the interval from diagnosis to treatment decreased. This study suggests that cancer screening played a significant role in the decline in cancer diagnosis that occurred during the COVID‐19 pandemic. Even under COVID‐19 pandemic conditions, there should be an awareness of cancer screening and endoscopic follow‐up.