Unravelling the structural complexity of glycolipids with cryogenic infrared spectroscopy

Glycolipids are complex glycoconjugates composed of a glycan headgroup and a lipid moiety. Their modular biosynthesis creates a vast amount of diverse and often isomeric structures, which fulfill highly specific biological functions. To date, no gold-standard analytical technique can provide a comprehensive structural elucidation of complex glycolipids, and insufficient tools for isomer distinction can lead to wrong assignments. Herein we use cryogenic gas-phase infrared spectroscopy to systematically investigate different kinds of isomerism in immunologically relevant glycolipids. We show that all structural features, including isomeric glycan headgroups, anomeric configurations and different lipid moieties, can be unambiguously resolved by diagnostic spectroscopic fingerprints in a narrow spectral range. The results allow for the characterization of isomeric glycolipid mixtures and biological applications

Mechanical Dissipation in Silicon Flexures

The thermo-mechanical properties of silicon make it of significant interest as a possible material for mirror substrates and suspension elements for future long-baseline gravitational wave detectors. The mechanical dissipation in 92um thick single-crystal silicon cantilevers has been observed over the temperature range 85 K to 300 K, with dissipation approaching levels down to phi = 4.4E-7.Comment: 7 pages. Accepted by Phys Lett A, submitted for publication on 28 October 200

Morpho-molecular ex vivo detection and grading of non-muscle-invasive bladder cancer using forward imaging probe based multimodal optical coherence tomography and Raman spectroscopy

Non-muscle-invasive bladder cancer affects millions of people worldwide, resulting in significant discomfort to the patient and potential death. Today, cystoscopy is the gold standard for bladder cancer assessment, using white light endoscopy to detect tumor suspected lesion areas, followed by resection of these areas and subsequent histopathological evaluation. Not only does the pathological examination take days, but due to the invasive nature, the performed biopsy can result in significant harm to the patient. Nowadays, optical modalities, such as optical coherence tomography (OCT) and Raman spectroscopy (RS), have proven to detect cancer in real time and can provide more detailed clinical information of a lesion, e.g. its penetration depth (stage) and the differentiation of the cells (grade). In this paper, we present an ex vivo study performed with a combined piezoelectric tube-based OCT-probe and fiber optic RS-probe imaging system that allows large field-of-view imaging of bladder biopsies, using both modalities and co-registered visualization, detection and grading of cancerous bladder lesions. In the present study, 119 examined biopsies were characterized, showing that fiber-optic based OCT provides a sensitivity of 78% and a specificity of 69% for the detection of non-muscle-invasive bladder cancer, while RS, on the other hand, provides a sensitivity of 81% and a specificity of 61% for the grading of low- and high-grade tissues. Moreover, the study shows that a piezoelectric tube-based OCT probe can have significant endurance, suitable for future long-lasting in vivo applications. These results also indicate that combined OCT and RS fiber probe-based characterization offers an exciting possibility for label-free and morpho-chemical optical biopsies for bladder cancer diagnostics. © 2020 The Royal Society of Chemistry

Effectiveness of initiating treatment with valsartan/hydrochlorothiazide in patients with stage-1 or stage-2 hypertension

This prospective, 6-week, multicenter, double-blind study examined the benefits of initiating treatment with combination valsartan/hydrochlorothiazide (HCTZ) compared with initial valsartan monotherapy for 648 patients with stage-1 or stage-2 hypertension (age=52.6±10 years; 54% male; baseline blood pressure (BP)=161/98 mm Hg, 32% stage 1). Patients were randomized to valsartan 80 mg (V-low), valsartan 160 mg (V-high) or valsartan/HCTZ 160/12.5 mg (V/HCTZ), and electively titrated after weeks 2 and 4 to the next dosage level (maximum dose valsartan/HCTZ 160/25 mg) if BP remained >140/90 mm Hg. At end of the study, patients initiated with V/HCTZ required less titration steps compared with the initial valsartan monotherapy groups (63 vs 86% required titration by study end, respectively) and reached the target BP goal of <140/90 mm Hg in a shorter period of time (2.8 weeks) (P<0.0001) vs V-low (4.3 weeks) and V-high (3.9 weeks). Initial combination therapy was also associated with higher BP control rates and greater reductions in both systolic and diastolic BP from baseline (63%, −27.7±13/–15.1±8 mm Hg) compared with V-low (46%, −21.2±13/−11.4±8 mm Hg, P<0.0001) or V-high (51%, −24.0±13/−12.0±10 mm Hg, P<0.01). Overall and drug-related AEs were mild to moderate and were similar between V/HCTZ (53.1 and 14.1%, respectively) and the two monotherapy groups, V-low (50.5 and 13.8%) and V-high (50.7 and 11.8%). In conclusion, initiating therapy with a combination of valsartan and low-dose HCTZ results in early, improved BP efficacy with similar tolerability as compared with starting treatment with a low or higher dose of valsartan for patients with stage-1 and stage-2 hypertension