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In this study, we introduce a novel optical setup tailored for measuring scattering spectra of small biological aggregates with minimal sample volumes. Calibration was achieved using Polystyrene beads (PS beads) based on Mie scattering principles, enabling accurate measurements of scattering intensities. Bovine serum albumin (BSA) served as a model for studying protein aggregation due to its predictable aggregation behaviour at elevated temperatures. Analysis of non-aggregated and aggregated BSA solutions revealed significant differences in particle size, underscoring the setup's capability to detect variations in aggregation states. Key findings demonstrate the system's efficacy in monitoring protein aggregation processes, which is critical for biochemical and pharmaceutical research. The precise calibration method and the use of BSA as a validation tool highlight the setup's sensitivity and accuracy in quantifying changes in particle concentration and size due to aggregation. This study provides a framework for analysing protein aggregation and offers insights into the aggregation's impact on scattering properties.

Background: Physicians and other health care personnel rely on the peer-reviewed biomedical literature as a key source for making clinical decisions. Thus, ensuring that the nonclinical and clinical findings published in biomedical journals are reported accurately and clearly, without undue influence from commercial interests, is essential. Accordingly, beginning in the mid-1990s and continuing to the present, various organizations, including the International Committee of Medical Journal Editors, the American Medical Association, the Council of Science Editors, the American Medical Writers Association, and the International Society for Medical Publication Professionals, have published guidelines to strengthen and uphold ethical standards in biomedical communications.Scope: A task force of staff members from the AXIS group of companies reviewed these and other guidelines to assess the need for a good publication practices (GPP) document specific to medical communications agencies. As this review demonstrated an unmet need, the task force was charged with developing GPP guidelines for the AXIS group of agencies in the United States.Findings: Although such guidelines have been previously published on behalf of medical journal editors and publishers, medical writers, academic centers, and pharmaceutical companies, there has been no prior publication in the peer-reviewed literature of good publication practices for medical communications agencies, which face unique challenges in negotiating a balance among authors, sponsoring companies, and biomedical publishers.Conclusion: This article presents and discusses these GPP guidelines. To our knowledge, this is the first publication of guidelines developed from the perspective of a medical communications agency. [ABSTRACT FROM AUTHOR]

Small-Angle Neutron Scattering (SANS) and Dynamic Light Scattering (DLS) are two crucial techniques to probe, respectively, the static and the dynamic structure factor of soft matter systems. Representative examples of DLS intensity autocorrelation functions, I g i SB 2 sb ( I Q i , I t i )-1, and the corresponding SANS data, I I i ( I Q i ), obtained on the LOQ instrument, are shown in Figure 2. (a, b) DLS intensity autocorrelation functions and (d, e) SANS intensities as simultaneously obtained from the PLS sample and the PNIPAM microgels using the DLS-SANS apparatus on (c) the LOQ instrument. [Extracted from the article]

Clay-polymer dispersions in aqueous solutions are of great interest due to their industrial applications and intriguing physical properties. Aqueous solutions of bare Laponite particles age spontaneously, from an ergodic to a non-ergodic state, in a time varying from hours to months depending on Laponite concentration. When a polymer species, such as polyethylene oxide (PEO), is added to the solution, it weakly adsorbs on clay particle surfaces modifying the effective interaction potential between Laponite particles. A dynamic light-scattering study was performed to investigate the effect of polymer on the aging dynamics of the system by varying the polymer concentration at a fixed polymer molecular weight (Mw = 200,000 g/mol). The results show that arresting phenomena between clay particles are hindered when PEO is added and, thus, a slowing of the aging dynamics with increasing PEO concentration is observed. A possible mechanism is progressive coverage of the clay surface by polymers, which grow with increasing PEO concentration. [ABSTRACT FROM AUTHOR]

The ageing dynamics of a charged colloidal system, Laponite suspended in water, have been investigated by photon correlation technique. The samples covered a novel and very wide range of clay concentrations (Cw = 0.3-3.1 wt%) and four different NaCl concentrations (Cs = 1 × 10-4 M, 1 × 10-3 M, 2 × 10-3 M and 5 × 10-3 M) and were studied to investigate the phase diagram, which has been a subject of discussion in recent literature. A clear picture of the Laponite phase diagram has been obtained. The measurements show the existence of two different dynamical routes to reach a final arrested state and the presence of a transition line between them in the Cw-Cs plane. [ABSTRACT FROM AUTHOR]

The incline and length of guiding elements, i.e. marginal ridges and lingual surfaces of front teeth, marginal ridges and internal cusp slopes of premolars and molars, play an important role in dentistry. Since the so far reported values differ considerably, it was the purpose of the present investigation to replicate the measurements, including all the occlusal landmarks proposed and defined by previous investigators. The measurements were performed on 34 pairs of mounted casts from a selected group of untreated, naturally grown dentitions from adolescents of mean age 14 years. The upper casts were mounted with a face bow, the kinematic hinge axis and the left incisura infraorbitalis representing the posterior and anterior reference points. The lower pinned casts were mounted joint related. All measurements were carried out with a computer-aided, three-dimensional digitizer. The inclines were expressed as angles related to the axis-orbital-plane. Taking the proposed occlusal landmarks as a basis, the inclines of guiding elements were found to be in agreement with previously reported values, despite ethnic and racial differences of the various study-populations. The values, however, differed markedly when measurements based on individual, functional relevant landmarks were compared to measurements based on anatomical, easy identifiable or mathematically constructed landmarks. The successive decrease of the inclines of the guiding elements from the central incisors to the second molars could be confirmed, the molars displaying very flat inclines. Interestingly, 9% of the first molars and 21% of the second molars showed negative values, pointing to a functional arrangement characterized by a buccally oriented occlusal surface of those teeth. Combined with the finding that the length of the guiding elements of the anterior teeth was almost twice as long as that of the posterior teeth, the results corroborate the occlusal concept of an anterior–posterior... [ABSTRACT FROM AUTHOR]

DynamicLightScattering(DLS)measurements were performed on colloidal suspensions ofLaponite atdiffer- ent concentrations in the range Cw = (1.5 3.0)%. The slowing down of the dynamics induced by aging was monitored byfollowingthetemporal evolution of autocorrelation functionsatdifferentconcentrations towards the gel and glass transition. Exploiting analogies with supercooled liquids approaching their glass transitions, an Angell plot for the structural relaxation times was drawn. Finally, the fragility ofLaponite suspensions at differentconcentrations, in differentsolvents, attwosaltconcentrationsand with theaddition of a polymerwas reported and discussed. [ABSTRACT FROM AUTHOR]

The process of dynamical arrest, leading to formation of different arrested states such as glasses and gels, along with the closely related process of aging, is central for both basic research and technology. Here we report on a study of the time-dependent structural evolution of two aqueous Laponite clay suspensions at different weight concentrations. Neutron diffraction experiments have been performed with the near and intermediate range order diffractometer (NIMROD) that allows studies of the structure of liquids and disordered materials over a continuous length scale ranging from 1 to 300 Å, i.e., from the atomistic to the mesoscopic scales. NIMROD is presently a unique diffractometer, bridging the length scales traditionally investigated by small angle neutron scattering or small angle x-ray scattering with that accessible by traditional diffractometers for liquids. Interestingly, we have unveiled a signature of aging of both suspensions in the length scale region of NIMROD. This phenomenon, ascribed to sporadic contacts between Laponite platelets at long times, has been observed with the sample arrested as gel or as repulsive glass. Moreover, water molecules within the layers closest to Laponite platelets surface show orientational and translational order, which maps into the crystalline structure of Laponite. [ABSTRACT FROM AUTHOR]

A chemical hydrogel based on telechelic poly(vinyl alcohol) and a physical synergic hydrogel, xanthan–glucomannan, were studied by means of dynamic light scattering technique. Two different nonergodic methods, due to Pusey et al. (Physica A 157 (1989) 705, Phys. Rev. A 42 (1990) 2161) and Xue et al. (Phys. Rev. A 46 (1992) 6550), were used to obtain the correct dynamic structure factors f(q,t). Good agreement between the results obtained with the two procedures was found. The behavior of the f(q,t) for different q vectors is consistent with the hypothesis that the nonfluctuating component in the scattered light is not due to microscopic heterogeneities but to restricted motion of the scatterers. The model of Krall et al. (Phys. Rev. Lett. 80 (1998) 778, Physica A 235 (1997) 19) was successfully applied to both hydrogels to extract the characteristic parameters of the network from the f(q,t) functions. [Copyright &y& Elsevier]