Risk factors for medication-related short-term readmissions in adults - a scoping review.

BACKGROUND: Hospital readmissions due to medication-related problems occur frequently, burdening patients and caregivers emotionally and straining health care systems economically. In times of limited health care resources, interventions to mitigate the risk of medication-related readmissions should be prioritized to patients most likely to benefit. Focusing on general internal medicine patients, this scoping review aims to identify risk factors associated with drug-related 30-day hospital readmissions. METHODS: We began by searching the Medline, Embase, and CINAHL databases from their inception dates to May 17, 2022 for studies reporting risk factors for 30-day drug-related readmissions. We included all peer-reviewed studies, while excluding literature reviews, conference abstracts, proceeding papers, editorials, and expert opinions. We also conducted backward citation searches of the included articles. Within the final sample, we analyzed the types and frequencies of risk factors mentioned. RESULTS: After deduplication of the initial search results, 1159 titles and abstracts were screened for full-text adjudication. We read 101 full articles, of which we included 37. Thirteen more were collected via backward citation searches, resulting in a final sample of 50 articles. We identified five risk factor categories: (1) patient characteristics, (2) medication groups, (3) medication therapy problems, (4) adverse drug reactions, and (5) readmission diagnoses. The most commonly mentioned risk factors were polypharmacy, prescribing problems-especially underprescribing and suboptimal drug selection-and adherence issues. Medication groups associated with the highest risk of 30-day readmissions (mostly following adverse drug reactions) were antithrombotic agents, insulin, opioid analgesics, and diuretics. Preventable medication-related readmissions most often reflected prescribing problems and/or adherence issues. CONCLUSIONS: This study's findings will help care teams prioritize patients for interventions to reduce medication-related hospital readmissions, which should increase patient safety. Further research is needed to analyze surrogate social parameters for the most common drug-related factors and their predictive value regarding medication-related readmissions.

Electron phase-space control in photonic chip-based particle acceleration.

Particle accelerators are essential tools in science, hospitals and industry1-6. Yet their costs and large footprint, ranging in length from metres to several kilometres, limit their use. The recently demonstrated nanophotonics-based acceleration of charged particles can reduce the cost and size of these accelerators by orders of magnitude7-9. In this approach, a carefully designed nanostructure transfers energy from laser light to the particles in a phase-synchronous manner, accelerating them. To accelerate particles to the megaelectronvolt range and beyond, with minimal particle loss10,11, the particle beam needs to be confined over extended distances, but the necessary control of the electron beam's phase space has been elusive. Here we demonstrate complex electron phase-space control at optical frequencies in the 225-nanometre narrow channel of a silicon-based photonic nanostructure that is 77.7 micrometres long. In particular, we experimentally show alternating phase focusing10-13, a particle propagation scheme for minimal-loss transport that could, in principle, be arbitrarily long. We expect this work to enable megaelectronvolt electron-beam generation on a photonic chip, with potential for applications in radiotherapy and compact light sources9, and other forms of electron phase-space control resulting in narrow energy or zeptosecond-bunched beams14-16.

Ponderomotive Generation and Detection of Attosecond Free-Electron Pulse Trains.

Atomic motion dynamics during structural changes or chemical reactions have been visualized by pico- and femtosecond pulsed electron beams via ultrafast electron diffraction and microscopy. Imaging the even faster dynamics of electrons in atoms, molecules, and solids requires electron pulses with subfemtosecond durations. We demonstrate here the all-optical generation of trains of attosecond free-electron pulses. The concept is based on the periodic energy modulation of a pulsed electron beam via an inelastic interaction, with the ponderomotive potential of an optical traveling wave generated by two femtosecond laser pulses at different frequencies in vacuum. The subsequent dispersive propagation leads to a compression of the electrons and the formation of ultrashort pulses. The longitudinal phase space evolution of the electrons after compression is mapped by a second phase-locked interaction. The comparison of measured and calculated spectrograms reveals the attosecond temporal structure of the compressed electron pulse trains with individual pulse durations of less than 300 as. This technique can be utilized for tailoring and initial characterization of suboptical-cycle free-electron pulses at high repetition rates for stroboscopic time-resolved experiments with subfemtosecond time resolution.

Acceleration of sub-relativistic electrons with an evanescent optical wave at a planar interface.

We report on a theoretical and experimental study of the energy transfer between an optical evanescent wave, propagating in vacuum along the planar boundary of a dielectric material, and a beam of sub-relativistic electrons. The evanescent wave is excited via total internal reflection in the dielectric by an infrared (λ = 2 µm) femtosecond laser pulse. By matching the electron propagation velocity to the phase velocity of the evanescent wave, energy modulation of the electron beam is achieved. A maximum energy gain of 800 eV is observed, corresponding to the absorption of more than 1000 photons by one electron. The maximum observed acceleration gradient is 19 ± 2 MeV/m. The striking advantage of this scheme is that a structuring of the acceleration element's surface is not required, enabling the use of materials with high laser damage thresholds that are difficult to nano-structure, such as SiC, Al2O3 or CaF2.

Optical gating and streaking of free electrons with sub-optical cycle precision.

The temporal resolution of ultrafast electron diffraction and microscopy experiments is currently limited by the available experimental techniques for the generation and characterization of electron bunches with single femtosecond or attosecond durations. Here, we present proof of principle experiments of an optical gating concept for free electrons via direct time-domain visualization of the sub-optical cycle energy and transverse momentum structure imprinted on the electron beam. We demonstrate a temporal resolution of 1.2±0.3 fs. The scheme is based on the synchronous interaction between electrons and the near-field mode of a dielectric nano-grating excited by a femtosecond laser pulse with an optical period duration of 6.5 fs. The sub-optical cycle resolution demonstrated here is promising for use in laser-driven streak cameras for attosecond temporal characterization of bunched particle beams as well as time-resolved experiments with free-electron beams.

A novel neuro-muscular marker for the heavy subunit of neurofilament proteins, NF-H, and striated muscle myosin of Xenopus laevis.

A novel monoclonal antibody, M7, is described, that reacts on Western blots with the large subunit of the neurofilament triplet proteins (NF-H) and with striated muscle myosin of Xenopus laevis. Enzymatically digested neurofilament and myosin proteins revealed different immunoreactive peptide fragments on Western blots. Therefore, the antibody must react with immunologically related epitopes common to both proteins. Immunohistochemistry showed staining of large and small axons in CNS and PNS, and nerves could be followed into endplate regions of skeletal muscles. These muscles were characterized by a striated immunostaining of the M-lines. Despite the crossreactivity of M7 with NF-H and muscle myosin, this antibody may be a tool to study innervation of muscle fibers, and to define changes in the neuromuscular organization during early development and metamorphosis of tadpoles.

Barrelfield expansion after neonatal eye removal in mice.

We investigated the effect of neonatal eye removal on the tangential extent of the barrelfield in mice. Areas were measured in drawings made from tangentially cut Nisslstained sections of somatosensory cortex. We compared areas of 29 barrels, corresponding to 29 mystacial vibrissae, between adult mice enucleated at birth (n = 13) and their intact littermates (n = 13). Multivariate analysis of variance showed that the barrelfield was larger in enucleated mice. This expansion was mainly due to the increase in areal extent of the barrels corresponding to the dorsalmost row of vibrissae, and of a set of barrels corresponding to rostral vibrissae near the nose and mouth. Evidently, early enucleation has a significant cross-modal effect on the somatosensory cortex.

Excessive numbers of axons after early enucleation and blockade of metamorphosis in the oculomotor nerve of Xenopus laevis.

The number of axons in the oculomotor (OM) nerve of Xenopus laevis tadpoles was counted in unoperated and in unilaterally enucleated animals, raised in 0.4 g/l thiourea (TU), a thyroid-blocking agent, which arrested their development at premetamorphosis. In unoperated animals the number of axons starts to decrease with metamorphosis. When raised in TU, the tadpoles do not metamorphose and show no axon loss; rather, there is a moderate increase in axon number (13%) after 6 months of thiourea-treatment. Thus metamorphosis is necessary for the initiation of axon loss. In unilaterally enucleated tadpoles, increased axon loss occurs at metamorphosis in the OM nerve of the operated side, but the contralateral OM nerve shows no loss at all. When these animals are treated with TU, there is, as compared with the effects of the TU-treatment in unoperated animals, an increase of 7% in the ipsilateral side and of 28% in the contralateral one. Thus thyroxine blockade prevents the effects of unilateral enucleation and induces an excessive number of axons during the period observed. We postulate that through blockade of metamorphosis, axon elimination is arrested, while their production continues, and that these effects are accentuated by manipulation of the axonal target.

The time course of the changes in axon number of both oculomotor nerves in normal and unilaterally enucleated Xenopus laevis.

UNLABELLED: In this paper we analyze long-term changes, extending into adulthood, of the number of axons in the oculomotor nerve of Xenopus laevis. We counted the number of axons in that nerve in normal control (nor) animals, and on the operated (ipsilateral, ip) and contralateral (co) sides of enucleated animals at premetamorphosis, metamorphic climax, juvenile (3 and 7 months) and adult (16.5 months) stages. The experimental animals had had one of their ocular primordia removed at hatching. In the nor-nerves there is a loss of 23% of the axons between premetamorphosis and climax, then a further drop of 35% by the 3-month stage, followed by a gain of 39% on reaching adulthood. At premetamorphosis the ip-nerves already contain less than the normal number of axons, which is reduced a further 73% by 3 months; there is no subsequent increase in adulthood. The co-nerves lose no axons from premetamorphosis to climax; they therefore have 30% more axons than normals; this excess is kept until 7 months; from then to sexual maturity the increase is only 11%. CONCLUSIONS: (1) unilateral target removal affects also the nerve innervating the contralateral target: the increased loss of axons on the operated side is accompanied by reduced loss on the other; (2) the contralateral side displays for some time an excess of axons compared to normal, but this is finally cancelled out by the addition of many axons in the adult nor animals; (3) adjustment of axon number is not restrained to embryonic stages but continues at least until sexual maturation.(ABSTRACT TRUNCATED AT 250 WORDS)

Axon number in oculomotor nerves in Xenopus: removal of one eye primordium affects both sides.

Unilateral removal of one eye primordium from Xenopus laevis embryos affects the number of axons in both oculomotor nerves: on the side of the operation, we observed a substantial decrease, and on the contralateral side an increase of over 30%. Mechanisms that may be invoked to explain this striking increase are: sprouting, rerouting of axons, decreased death of the motoneurones involved, and abnormal survival of ephemeral axon collaterals.

Detergent-soaked HRP-chips: a new method for precise and effective delivery of small quantities of the tracer to nervous tissue.

We dissolved horseradish peroxidase (HRP) in a 5% aqueous detergent solution (Nonidet P-40) and dried it to a solid mass which was then fragmented into small chips of convenient size. These were applied to the cut or crushed oculomotor nerves of Xenopus laevis tadpoles. This method combines the advantages of solid HRP (high concentration) and the presence of a detergent (enhanced uptake). Moreover, as compared to chips of HRP alone, addition of the detergent facilitated the manipulation of the chips.

Evidence for hemocyanin formation in the compound eye of Squilla mantis (Crustacea, Stomatopoda).

In the retina and in the subretinal space of the compound eye of Squilla mantis a special kind of pigment cell is present. The crystalline inclusions of this cell have been identified as hemocyanin, as determined (i) by the dimensional congruence of the crystalline substructure with the dimensions of isolated, purified hemocyanin, and (ii) by the immunofluorescence reaction using anti-hemicyanin antibodies. The ultrastructure of these cells, their location and the presence of crystalline bodies in their cytoplasm suggest that they are sites of hemocyanin synthesis and homologous to the cyanocytes or cyanoblasts of Limulus.

Ultrastructure and cytochemistry of the yolk syncytial layer in the alevin of trout (Salmo fario trutta L. and Salmo gairdneri R.) after hatching. II. The cytoplasmic zone.

In contrast to the vitellolysis zone which is involved in the degradation of the yolk, the cytoplasmic zone of the yolk syncytial layer, composed of many cytoplasmic organelles, is implicated in a secretory process. The granular endoplasmic reticulum of the latter is extremely well developed and organized into trabeculae. The yolk nuclei show a RNA positive reaction. The Golgi apparatus is implicated in the elaboration of very low density lipoproteins (VLDL) and of acid phosphatase. The numerous mitochondria seem to suggest an important energy metabolism in the solubilisation area. The appearance of certain special structures (crystalline bodies, pseudovesicular structures, lipochondria) as well as their relation with the organelles of the cytoplasmic zone, re-inforces the impression of a layer with a secretory nature and suggests its participation in the remodelling of the yolk products produced in the vitellolysis zone. The results of the investigations concerning the acid phosphatase activity suggest that this enzyme plays a role on the one hand in the degradation of certain platelets which penetrate into the cytoplasmic zone, and on the other hand in the regulation of VLDL, in the lysis of secretory products elaborated by the cytoplasmic zone. The possible presence of microperoxisomes is discussed as well as the positive detection of glucose-6-phosphate dehydrogenase.

Ultrastructure and cytochemistry study of the yolk syncytial layer in the alevin of trout (Salmo fario trutta L.) after hatching. I. The vitellolysis zone.

After hatching, the yolk syncytial layer of Salmo fario trutta may be subdivided into two zones, namely, the vitellolysis zone (containing numerous yolk platelets), and the cytoplasmic zone (where yolk platelets are rare). In the vitellolysis zone, two stages in the utilization of the yolk are observed: 1) The first stage, comprises the formation of yolk platelets from coalescent yolk by spherical cutting out and basal scission. This process seems to be achieved by the invagination of fibrillar elements into the coalescent yolk to form individual yolk platelets surrounded by a limiting membrane. 2) The second stage essentially consists of the extrusion or budding of yolk matter from a yolk platelet. Again, where the yolk matter leaves a platelet, fibrillar elements are evident and show an alkaline phosphatase activity. The platelets of the vitellolysis zone have a homogeneous content and variable diameter; they never acquire a heterogeneous and polymorphic aspect which could be interpreted as an intermediate stage in their degradation.

The fine structure of the compound eye of Squilla mantis (Crustacea, Stomatopoda).

The fine structure of the compound eye of adult specimens of Squilla mantis was investigated. The eye consists of about 3600-3700 ommatidia, each containing a dioptric apparatus formed by a lamellated corneal lens and a eucone-type crystalline cone. Each of the four cone cells give rise to a cylindrical process (crystalline thread) inserted between the retinula cells and extending down to the basement membrane. Two distal pigment cells completely encompass the distal part of the crystalline cone, becoming progressively smaller and forming roundish processes. At the level of the tip of the crystalline cone they split off into small pigment-containing processes, and a central process leads down to the basement membrane. About 12-16 proximal pigment cells surround the ommatidium and extend from the tip of the crystalline cone to the basement membrane. In addition to the two types of pigment cell, three other types of pigment-containing cells were identified, one of which possibly contains - on the basis of their ultrastructure - crystals of the respiratory pigment hemocyanin. The two other pigments are found respectively on the surface of the retina (green pigment) and beneath the surface and in the intraommatidial space (white pigment). The distal part of each ommatidium consists of retinula cells of about equal size. Further proximal an 8th small retinula cell is encountered. The fused, centrally located rhabdom, is built up of the microvilli (rhabdomeres) of the 7 large retinula cells, the 8th has no microvilli. The structure of the ommatidia was also examined in relation to light-dark adapted conditions (LA-DA). In DA the crystalline cone shortens and the rhabdom becomes longer by an approximately corresponding amount and the pigments of the distal pigment cells expand more distally. The number and type of special cytoplasmic inclusions, as well as the shape and size of the so-called perirhabdomal vacuoles, seems not to be changed by light or dark-adaptation. In the 7 large retinula cells, an unusual migration of pigment granules occurs under DA conditions (the 8th does not contain pigment granules), In DA, many of granules which are distributed around the rhabdom in LA, line up in rows, like strings of pearls, along the rhabdom, forming a dense pigment coat around it. The findings are compared with those of related studies and their functional implications for the vision of Squilla are discussed.

[Ultrastructure of nephridial systems in cyclophyllidean cestoda: Catenotaenia pusilla (Goeze, 1782), Hymenolepis diminuta (Rudolphi, 1819) and Inermicapsifer madagascariensis (Davaine, 1870) Baer, 1956]. / Ultrastructures du système néphridien des cestodes cyclophyllides Catenotaenia pusilla (Goeze, 1782) Hymenolepis diminuta (Rudolphi, 1819) et Inermicapsifer madagascariensis (Davaine, 1870) Baer, 1956

Electron microscopic study of nephridial systems in three cyclophyllidean cestodes indicates a resemblance in their ultrastructure. The walls of longitudinal, transverse and collecting ducts show a very similar pattern of organization. The surface of the anucleate epithelium lining the ducts is developed into microvilli. A relatively thick layer of fibrillar tissue underlies the basal membrane of the microvillar epithelium. The nucleated portions or "pericaryons", situated between the parenchymal cells, are directly connected with epithelium by cytoplasmic prolongations. The canalicular lumen extends through a single series of cells curved into a ring. The epithelial surface of the canalicular wall is developed into short, densly staining microvilli and the immediately underlying fibrillar tissue appears very compact. The cilia were never observed in any of the above ducts. The ultrastructure of protonephridia proper is comparable with those already described in other cestodes. There is a close association between the flame-cell and the cancalicular ending, enlarged into a nephridial funnel. A single row of nephridial rods of the flame-cell is surrounded by a row of digitiform prolongations of the nephridial funnel border. The prolongations alternate with the rods and their interlocking pattern appears clearly in cross-sections. A series of minute pores or "nephrostomes" providing a direct contact between the nephridial chamber and intercellular space of the paranchyma was shown. The problem of classification and definition between the "closed" protonephridia and open metanephridia is discussed. The structural unity of protonephridia in different groupes of Platyhelminthes is reviewed. The different number of flagella within the "flames" of different cestodes is compared and analyzed. The ultrastructural characteristics of duct-wall epithelium provides some confirmation of its high metabolic activity.