A Novel Recycling Route for Spent Li-Ion Batteries

In this work, a recycling route for spent Li-ion batteries (LIBs) was developed. For this, the recovery of the metal content in both electrodes (anode and cathode) was investigated. Based on these results, an economic analysis of this recycling process was carried out. The obtained results showed that more than 90% of the material contained in both electrodes was recycled. The dissolution with acetic acid of the metals present in the active cathodic material is thermodynamically viable and the addition of a reducing agent such as hydrogen peroxide improved the spontaneity of the reaction. Dissolutions close to 100% for Li and Co were obtained. In addition, it was determined that the synthesis of lithium and cobalt valuable compounds was viable from the leach liquor, recovering approximately 90% of Co as cobalt oxalate, and 92% of Li as lithium carbonate. Furthermore, carbon graphite and Cu were fully recovered (100%) from the anodes. Finally, the results of the economic analysis showed that the recovered products have a high commercial value and industrial interest, providing an environmentally and economically viable process.     

Time and exposure to serotonin affect releasability of recycled vesicles at crayfish claw opener muscle synapses

The crayfish claw opener neuromuscular junction is a biological model for studying presynaptic neuromodulation by serotonin (5HT) and synaptic vesicle recycling. It has been hypothesized that 5HT enhances release by recruiting a population of either previously nonrecycling or “reluctant” vesicles to increase the readily releasable pool. To determine if 5HT activates a distinct population of synaptic vesicles, recycling membranes were labeled with the membrane dye, FM1-43. Unloading (destaining) protocols could not resolve a population of vesicles that were only releasable in the presence of 5HT. Instead, we conclude synaptic vesicles change behavior in axon terminals independent of 5HT, becoming less likely to exocytose and unload dye over periods of >1 hr after recycling. We hypothesized this to be due to the slow conversion of a portion of recycled vesicles to a difficult to release state. The possibility that vesicles in these pools were spatially separated within the terminal was tested using photoconversion of FM1-43 and transmission electron microscopy. The location of FM1-43-labeled vesicles fixed 2 min following 3 min of 20-Hz stimulation did not reveal preferential localization of recycling vesicles specifically near release sites and the distribution of labeled vesicles was not significantly different between early (2 min) and late (180 min) time points. Terminals fixed 30 s following stimulation contained a significant proportion of vesicular structures equivalent in diameter to 2–5 regular vesicles, with multivesicular bodies and calveoli rarely seen, suggesting that endocytosis during sustained release at crayfish terminals occurs via multiple routes, most commonly through large “vesicle” intermediates.     

In vivo synaptic recovery following optogenetic hyperstimulation

Local recycling of synaptic vesicles (SVs) allows neurons to sustain transmitter release. Extreme activity (e.g., during seizure) may exhaust synaptic transmission and, in vitro, induces bulk endocytosis to recover SV membrane and proteins; how this occurs in animals is unknown. Following optogenetic hyperstimulation of Caenorhabditis elegans motoneurons, we analyzed synaptic recovery by time-resolved behavioral, electrophysiological, and ultrastructural assays. Recovery of docked SVs and of evoked-release amplitudes (indicating readily-releasable pool refilling) occurred within ∼8–20 s (τ = 9.2 s and τ = 11.9 s), whereas locomotion recovered only after ∼60 s (τ = 20 s). During ∼11-s stimulation, 50- to 200-nm noncoated vesicles (“100nm vesicles”) formed, which disappeared ∼8 s poststimulation, likely representing endocytic intermediates from which SVs may regenerate. In endophilin, synaptojanin, and dynamin mutants, affecting endocytosis and vesicle scission, resolving 100nm vesicles was delayed (>20 s). In dynamin mutants, 100nm vesicles were abundant and persistent, sometimes continuous with the plasma membrane; incomplete budding of smaller vesicles from 100nm vesicles further implicates dynamin in regenerating SVs from bulk-endocytosed vesicles. Synaptic recovery after exhaustive activity is slow, and different time scales of recovery at ultrastructural, physiological, and behavioral levels indicate multiple contributing processes. Similar processes may jointly account for slow recovery from acute seizures also in higher animals.Efficient chemical synaptic neurotransmission requires synaptic vesicle (SV) biogenesis, transmitter loading, membrane approximation and docking, priming, fusion, and release of transmitter (1–3). These processes are followed by retrieval of membrane and proteins from the plasma membrane (PM) via endocytosis (4, 5). Particularly, sustained SV release relies on a tight coupling of exocytosis and endocytosis (5–8). During high-frequency or long-term neuronal activity, SVs need to be efficiently recycled, because, otherwise, the readily releasable pool and the (mobilized) resting pool of SVs would be depleted and transmission would seize (9, 10). After fusion, SV membranes and proteins are recycled (11). Coupling SV exocytosis with local recycling largely eliminates the dependence of chemical transmission on somatic de novo SV synthesis and transport. Thus far, these processes have been studied in dissected preparations or cultured cells and tissues; how and at which time scales this occurs within a live, nondissected animal (e.g., during seizures) is currently unclear. For example, patients suffering from a seizure often remain unconscious for minutes to hours (12, 13). Although fatigue at different levels of circuits and brain systems is likely to contribute, also physiological changes in chemical synapses may play a role in this slow recovery.Depending on the SV fusion rate, endocytosis occurs via different pathways: (i) clathrin-mediated endocytosis (14), supposedly accounting for most recycled SVs; (ii) fast “kiss-and-run” recycling, where SVs do not fully fuse but open a transient pore for transmitter release (15, 16); and (iii) clathrin-independent bulk-phase endocytosis, going along with high neuronal activity (17–20). Following membrane invagination, or to close the fusion pore, the GTPase dynamin finalizes, or at least speeds up, the process of membrane severing (21–25). Before scission by dynamin, the phospholipid phosphatase synaptojanin, via the membrane-binding Bin–amphiphysin–Rvs (BAR) domain protein endophilin, binds to the phospholipid enriched PM at endocytic sites and modifies lipids to promote scission (6, 26–28). Synaptojanin is also required after scission, particularly to uncoat endocytosed vesicles: by dephosphorylating the lipid head groups, synaptojanin releases the interaction of clathrin adaptors with the endocytosed membranes (27, 29). By recruiting clathrin adaptors, synaptotagmin/SNT-1 is also involved in SV recycling (30, 31).Across systems, different modes of endocytosis appear to be in effect: for example, in dynamin knockout mice, spontaneous activity induced endocytosed synaptic membrane, which appeared trapped as invaginations, tubulated and capped by clathrin-coated pits (21). Upon excessive stimulation, in inhibitory neurons, bulk-endocytosed, endosome-like structures resulted, which were severed from the PM despite the absence of dynamin (25). In neuron terminals of Drosophila in which clathrin function was acutely inhibited, SV recycling was impaired, whereas bulk endocytosis was still observed (22), and inhibition of dynamin uncovered different modes of SV recycling (32). Furthermore, when dynamin dephosphorylation was stalled, clathrin-mediated SV endocytosis was functional, but bulk endocytosis was affected (23). Thus, during moderate activity, SV recycling may occur by clathrin-mediated endocytosis (CME), to allow SV proteins to be retrieved and release sites to be “cleared” from integral membrane proteins. Upon prolonged or high-frequency activation, bulk endocytosis may follow in a clathrin-independent and, depending on synapse type, dynamin-dependent or -independent fashion, whereas resolution of the invaginated membrane structures may again be clathrin-dependent. However, in retinal bipolar cells, clathrin was required for a slow (τ ≈ 10–20 s) but not a fast (τ ≈ 1–2 s) phase of endocytosis (33), the latter of which was shown to depend on endophilin (34). In Caenorhabditis elegans, clathrin inactivation, surprisingly, had no effect on normal chemical transmission, and yet SV size was altered (35). Thus, it is unclear whether CME is required for SV endocytosis in C. elegans or is needed at a later step (e.g., following a different endocytic pathway) to shape new SVs. Bulk endocytosis can rapidly remove membrane material from the PM after excessive fusion of many SVs in vitro and was observed in experimental paradigms involving long-term electrical or chemical stimulation and pharmacological treatment (36–42), and yet it has not been studied in an intact animal.How the diverse endocytic events differentially contribute to the dynamic refilling of different SV pools is only partially understood. Because virtually all processes at active zones (AZs) occur at scales below the diffraction limit of light microscopy, it is difficult to study their dynamic behavior during and after stimulation. Therefore, electron microscopy (EM) has been the method of choice to analyze SV pools and AZ morphology at high resolution. Although previous work could visualize triggered SV exocytosis and endocytosis, these dynamic processes are difficult to analyze at high temporal resolution using classical EM (36–39). The dependence on slow chemical-fixation techniques precluded the capture of precise time points during dynamic events and limited the preservation of synaptic structures. Both problems may be overcome using cryofixation by high-pressure freeze (HPF)-EM (43, 44). The requirement of endophilin, synaptojanin, clathrin, and other proteins for SV endocytosis has been studied to some extent in C. elegans, also by EM (27, 28, 35, 43, 45–47). However, this was not done in a temporally resolved fashion relative to a stimulus (i.e., only steady-state “snapshots” were analyzed), and also HPF-EM has not yet been used in this context. How C. elegans synapses regulate endocytosis during and following periods of extreme activity, possibly by different modes of endocytosis, and which proteins are required for this, is unknown.Using a combination of channelrhodopsin-2 (ChR2)-mediated photostimulation of neurons and electrophysiological analysis in dissected animals (48, 49), as well as photostimulation followed by HPF-EM in intact animals, we monitored dynamic processes at AZs in three dimensions at EM resolution, and in a time-dependent manner. We studied the kinetics of docked SV depletion and recovery, as well as the generation and decomposition of bulk-endocytosed vesicles, during and following prolonged photostimulation. Whereas behavioral recovery required 60 s, synapses became fully competent to release transmitter only after ∼20 s, in line with morphological recovery of most docked SVs, whereas spontaneous release occurred at normal rates right after the stimulus. In addition, we found formation and disintegration of large (50–200 nm) bulk-endocytosed vesicles, within 11 and 8 s, respectively, the disassembly of which was largely delayed in animals expressing mutant endophilin, synaptojanin, and dynamin proteins.     

From the Cover: Global mapping of Al,Cu, Fe,and Zn in-use stocks and in-ground resources

Human activity has become a significant geomorphic force in modern times, resulting in unprecedented movements of material around Earth. An essential constituent of this material movement, the major industrial metals aluminium, copper, iron, and zinc in the human-built environment are mapped globally at 1-km nominal resolution for the year 2000 and compared with the locations of present-day in-ground resources. While the maps of in-ground resources generated essentially combine available databases, the mapping methodology of in-use stocks relies on the linear regression between gross domestic product and both in-use stock estimates and the Nighttime Lights of the World dataset. As the first global maps of in-use metal stocks, they reveal that a full 25% of the world''s Fe, Al, Cu, and Zn in-use deposits are concentrated in three bands: (i) the Eastern seaboard from Washington, D.C. to Boston in the United States, (ii) England, Benelux into Germany and Northern Italy, and (iii) South Korea and Japan. This pattern is consistent across all metals investigated. In contrast, the global maps of primary metal resources reveal these deposits are more evenly distributed between the developed and developing worlds, with the distribution pattern differing depending on the metal. This analysis highlights the magnitude at which in-ground metal resources have been translocated to in-use stocks, largely from highly concentrated but globally dispersed in-ground deposits to more diffuse in-use stocks located primarily in developed urban regions.     

The molecular adsorbents recycling system as a liver support system based on albumin dialysis: a summary of preclinical investigations, prospective, randomized, controlled clinical trial, and clinical experience from 19 centers

Artificial liver support aims to prolong survival time of patients with liver failure by detoxification. Albumin as a molecular adsorbent in dialysis solution is capable of attracting even tightly albumin-bound toxins from blood into the dialysate if a specific dialysis membrane is used and if the albumin's binding sites are on-line-purified by a sorbent/dialysis-based recycling system (i.e., molecular adsorbents recycling system, or MARS). The MARS technology has been shown to remove water-soluble and albumin-bound toxins and to provide renal support in case of renal failure. Fourteen centers have reported that MARS treatment improved mental status of patients with liver failure and hepatic encephalopathy. In treating liver failure and cholestasis, MARS was associated with hemodynamic stabilization, improvement of hepatic and kidney function, and disappearance of pruritus. In hepatic failure and hepatorenal syndrome, a prospective, randomized, controlled trial of MARS treatment was able to prolong survival time significantly. MARS has been used in 26 patients with acute liver failure or primary graft dysfunction. Nineteen centers reporting on 103 patients have shown that MARS treatment is safe, easy to handle, feasible, and effective.     

Synaptic vesicle endocytosis: the races,places, and molecular faces

The classical experiments on synaptic vesicle recycling in the 1970s by Heuser and Reese, Ceccarelli, and their colleagues raised opposing theories regarding the speed, mechanisms, and locations of membrane retrieval at the synapse. The Heuser and Reese experiments supported a model in which synaptic vesicle recycling is mediated by the formation of coated vesicles, is relatively slow, and occurs distally from active zones, the sites of neurotransmitter release. Because heavy levels of stimulation were needed to visualize the coated vesicles, Ceccarelli’s experiments argued that synaptic vesicle recycling does not require the formation of coated vesicles, is relatively fast, and occurs directly at the active zone in a “kiss-and-run” reversal of exocytosis under more physiological conditions. For the next thirty years, these models have provided the foundation for studies of the rates, locations, and molecular elements involved in synaptic vesicle endocytosis. Here, we describe the evidence supporting each model and argue that the coated vesicle pathway is the most predominant physiological mechanism for recycling synaptic vesicles.     

Expression of the vesicular glutamate transporters during development indicates the widespread corelease of multiple neurotransmitters

Three closely related proteins transport glutamate into synaptic vesicles for release by exocytosis. Complementary patterns of expression in glutamatergic terminals have been reported for VGLUT1 and VGLUT2. VGLUT3 shows expression by many cells not considered to be glutamatergic. Here we describe the changes in VGLUT expression that occur during development. VGLUT1 expression increases gradually after birth and eventually predominates over the other isoforms in telencephalic regions. Expressed at high levels shortly after birth, VGLUT2 declines with age in multiple regions, in the cerebellum by 14-fold. In contrast, Coexpression of the two isoforms occurs transiently during development as well as permanently in a restricted subset of glutamatergic terminals in the adult. VGLUT3 is transiently expressed at high levels by select neuronal populations, including terminals in the cerebellar nuclei, scattered neurons in the cortex, and progenitor-like cells, implicating exocytotic glutamate release in morphogenesis and development. VGLUT3 also colocalizes extensively during development with the neuronal vesicular monoamine transporter VMAT2, with the vesicular acetylcholine transporter VAChT, and with the vesicular gamma-aminobutyric acid transporter VGAT. Such coexpression occurs particularly at some specific developmental stages and is restricted to certain sets of cells. In skeletal muscle, VGLUT3 localizes to granular organelles in the axon terminal as well as in the muscle sarcoplasm. The results suggest novel mechanisms and roles for regulated transmitter release.     

台州过期药品回收现状及对策研究

针对台州市药品回收现状展开具有代表性的调查，经过调查分析发现目前药品回收“叫好不叫座”。其原因在于公众意识不高、群众对激励措施的需求和回收单位无偿费用支出之间存在矛盾等诸多方面。建议运用管理学的控制理论来实行药品回收活动的前期控制，同期控制和反馈控制，以达到好的效果。     

Determination of Trace Metals Using Laser Induced Breakdown Spectroscopy in Insoluble Organic Materials Obtained from Pyrolysis of Plastics Waste

Laser induced breakdown spectroscopy (LIBS) was applied for the detection of trace elements in non-degradable part of plastics known as insoluble organic material, obtained from thermal and catalytic degradation of plastics. LIBS signal intensity for each metal measured in the test sample was unique and different. The capability of this technique is demonstrated by analyzing various trace metals present inside plastics and also compared with ICP results. The metal concentration (ppm) measured with LIBS and verified by ICP for Ag (901), Al (522), Fe (231), Co (628), V (275), Ni (558), Pb (325), Mn (167) and Cd (378) are higher than permissible safe limits.