Nutritive value of treated Quercus infectoria and Quercus libani leaves with the tannin-degrading bacterium Klebsiella pneumoniae for ruminant feeding in vitro

AIMS

This study was conducted to evaluate the chemical composition and in vitro gas production (GP) and fermentation parameters of Quercus infectoria and Quercus libani leaves following treatment with the Klebsiella pneumoniae, a tannin-degrading bacterium.

METHODS AND RESULTS

This isolate was isolated on medium containing tannic acid as the sole source of carbon and energy, and identified based on 16S rRNA sequencing analysis. In both oak leaf species (i.e. Q. infectoria and Q. libani), inoculation with Klebsiella pneumoniae significantly increased (P < 0·05) dry matter (DM) loss. For Q. libani, crude protein content was increased (P = 0·02) by bacterial treatment vs. control. In both oak leaves, total phenolic content and total tannins were decreased (P < 0·05) as a consequence of bacterial treatment. However, bacterial processing didn't changed (P > 0·05) organic matter (OM), neutral detergent fibre, acid detergent fibre or acid detergent lignin content of treated leaves. In both oak leaves the measuring parameters including GP volume, in vitro digestibility of DM and OM, estimated metabolizable energy, total volatile fatty acids, acetate, ammonia nitrogen concentration, total protozoal population and the subfamily Isotricha in treatments were higher (P < 0·05) than control.

CONCLUSIONS

It can be concluded that biological treatment of Q. infectoria and Q. libani leaves with K. pneumoniae represents a useful approach to decrease their phenolic compound content and improve their nutritive value as ruminant feed.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study demonstrated that biologically processing of tannin-containing by-products with K. pneumoniae could increase their nutritive value as ruminant feeds and increase animal productivity.

Profiling of how nociceptor neurons detect danger - new and old foes

The host evolves redundant mechanisms to preserve physiological processing and homeostasis. These functions range from sensing internal and external threats, creating a memory of the insult and generating reflexes, which aim to resolve inflammation. Impairment in such functioning leads to chronic inflammatory diseases. By interacting through a common language of ligands and receptors, the immune and sensory nervous systems work in concert to accomplish such protective functions. Whilst this bidirectional communication helps to protect from danger, it can contribute to disease pathophysiology. Thus, the somatosensory nervous system is anatomically positioned within primary and secondary lymphoid tissues and mucosa to modulate immunity directly. Upstream of this interplay, neurons detect danger, which prompts the release of neuropeptides initiating (i) defensive reflexes (ranging from withdrawal response to coughing) and (ii) chemotaxis, adhesion and local infiltration of immune cells. The resulting outcome of such neuro-immune interplay is still ill-defined, but consensual findings start to emerge and support neuropeptides not only as blockers of T_H 1-mediated immunity but also as drivers of T_H 2 immune responses. However, the modalities detected by nociceptors revealed broader than mechanical pressure and temperature sensing and include signals as various as cytokines and pathogens to immunoglobulins and even microRNAs. Along these lines, we aggregated various dorsal root ganglion sensory neuron expression profiling datasets supporting such wide-ranging sensing capabilities to help identifying new danger detection modalities of these cells. Thus, revealing unexpected aspects of nociceptor neuron biology might prompt the identification of novel drivers of immunity, means to resolve inflammation and strategies to safeguard homeostasis.

Tuning the Structure of Pt Nanoparticles through Support Interactions: An in Situ Polarized X-ray Absorption Study Coupled with Atomistic Simulations

Interactions of nanoparticles (NPs) with their environment may have a pronounced effect on their structure and shape as well as on their functionality in applications such as catalysis. It is therefore crucial to disentangle the particle-adsorbate and particle-support interaction effects on the particle shape, its local structure, atomic dynamics, and its possible anisotropies. In order to gain insight into the support effect, we carried out an X-ray absorption fine-structure spectroscopy (XAFS) investigation of adsorbate- and ligand-free size-selected Pt NPs deposited on two different supports in ultrahigh vacuum. Polarization-dependent XAFS measurements, neural network-based analysis of X-ray absorption near-edge structure data, and reverse Monte Carlo (RMC) simulations of extended X-ray absorption fine structure (EXAFS) were used to resolve the 3D shape of the NPs and details of their local structure. A synergetic combination of advanced in situ XAFS analysis with atomic force microscopy and scanning tunneling microscopy (STM) imaging provides uniquely detailed information about the particle-support interactions and the NP/support buried interface, not accessible to any experimental technique, when considered alone. In particular, our combined approach reveals differences in the structure of Pt NPs deposited on TiO₂(110) and SiO₂/Si(111). Pt NPs on SiO₂ assume a spherical-like 3D shape and weakly interact with the support. In contrast, the effective shape of analogously synthesized Pt NPs on TiO₂(110) after annealing at 600 °C is found to be a truncated octahedron with (100) top and interfacial facets that are encapsulated by the TiO₂ support. Modeling disorder effects in these NPs using an RMC approach reveals differences in bond-length distributions for NPs on different supports and allows us to analyze their anisotropy, which may be crucial for the interpretation of support-dependent atomic dynamics and can have an impact on the understanding of the catalytic properties of these NPs.

Determination of neutron flux parameters (f, α, φth and φe) of the irradiation sites of Isfahan MNSR reactor using empirical and MCNPX2.6 simulation approaches

Miniature Neutron Source reactors (MNSRs) are ideal for applications such as nuclear research, neutron activation analysis, etc., provided that their neutron flux parameters (φ_th, φ_e, f and α) are known. This paper present the results of the neutron flux parameters at inner and outer irradiation sites of Isfahan MNSR reactor determined through simulation with MCNPX2.6 code and experimentally using bare and cadmium-covered gold foils irradiation and bare triple (AuZr) monitor methods. In empirical approach, the obtained φ_th, φ_e, f [f_bare] and α-values were 5.02 × 10¹¹ ncm^-2s^-1 (±4.5%), 3.13 × 10¹⁰ ncm^-2s^-1 (±2.3%), 16.0 (±6.7%) [17.3 (±9.9%)] and -0.121 (±0.2%), for inner site; and 2.93 × 10¹¹ ncm^-2s^-1 (±2.3%), 6.48 × 10⁹ ncm^-2s^-1 (±3.1%), 45.2 (±5.4%) [42.5 (±7.1%)] and -0.011 (±1.8%), respectively, for outer site. In simulation approach, while, they were found to be 4.76 × 10¹¹ ncm^-2s^-1 (±0.9%), 2.00 × 10¹⁰ ncm^-2s^-1 (±2.2%), 23.8 (±3.1%) and -0.078 (±0.13%), for the inner site; and 2.67 × 10¹¹ ncm^-2s^-1 (±1.1%), 3.79 × 10⁹ ncm^-2s^-1 (±5.4%), 70.4 (±6.5%) and -0.017 (±0.4%) for the outer site, respectively. Comparison of empirical and simulation results clearly revealed that: the inner site's φ_th and f values correspond with those measured during the first startup of the reactor; the values of φ_th are more reliable than φ_e,-values, as are the inner site's f and α results in comparison with outer site's values; the inner site's φ_th and φ_e are ∼1.7 and 5 times, respectively, larger than those of outer site; and the inner site 's α and f-values are more than 4.8 and 2.4 times larger and less than the outer site's values, respectively.

Salivary Biomarkers in Denture Stomatitis: A Systematic Review

OBJECTIVE

Denture stomatitis (DS) is an oral biofilm-associated inflammation of the denture-bearing mucosa. The objective of this review was to identify and evaluate the quality of evidence on the association between the levels of salivary biomarkers and DS among adults with and without palatal DS.

MATERIALS AND METHODS

Following the PRISMA guidelines, Medline, PubMed, EMBASE, and the Cochrane Central Register for Controlled Trials were searched for eligible studies from the beginning of the archives until December 2018. Experimental and observational studies with adult participants were included that had a control group or subgroup analysis and provided data on salivary biomarkers and DS. Articles in languages other than English or French were excluded. The level of evidence and grades of recommendation were established with the 2011 scale of the Oxford Centre for Evidence-Based Medicine. Additionally, the assessment of methodological quality was conducted with the STROBE statement (Strengthening the Reporting of Observational Studies in Epidemiology) and graded according to the Olmos scale.

RESULTS

From 1,008 citations, 9 studies were included in the systematic review (8 observational, 1 clinical trial). Seven studies suggested a statistically significant difference in the levels of salivary cytokines (IL-6, CCL3, TGF-β, CXCL8, GM-CSF, and TNF-α) between participants with DS and controls (P < 0.05). In contrast, 2 studies concluded that the difference in the levels of several salivary cytokines (IL2, IL12, IFN-g, IL-4, IL-8, IL-10, IL-17, TNF-α, and ICAM-1) between the groups was not statistically significant. The level of evidence for the majority of studies was 3, while the grade of recommendation for all the studies was B, interpreted as "favorable." In terms of methodological quality, most studies met 50% to 80% of STROBE criteria and were graded B.

CONCLUSION

Palatal inflammation in DS is significantly associated with the levels of salivary cytokines.

KNOWLEDGE TRANSFER STATEMENT

The results of this study identified altered levels of specific salivary biomarkers associated with denture stomatitis, which may aid in the early diagnosis and treatment of this disease.

Wnt and Notch signaling govern self-renewal and differentiation in a subset of human glioblastoma stem cells

In this study, Rajakulendran et al. investigated the role of Wnt/βcatenin signaling in GBM stem cell renewal and fate decisions. They identify new contexts for Wnt modulation for targeting stem cell differentiation and self-renewal in GBM heterogeneity.

Developmental signal transduction pathways act diversely, with context-dependent roles across systems and disease types. Glioblastomas (GBMs), which are the poorest prognosis primary brain cancers, strongly resemble developmental systems, but these growth processes have not been exploited therapeutically, likely in part due to the extreme cellular and genetic heterogeneity observed in these tumors. The role of Wnt/βcatenin signaling in GBM stem cell (GSC) renewal and fate decisions remains controversial. Here, we report context-specific actions of Wnt/βcatenin signaling in directing cellular fate specification and renewal. A subset of primary GBM-derived stem cells requires Wnt proteins for self-renewal, and this subset specifically relies on Wnt/βcatenin signaling for enhanced tumor burden in xenograft models. In an orthotopic Wnt reporter model, Wnt^hi GBM cells (which exhibit high levels of βcatenin signaling) are a faster-cycling, highly self-renewing stem cell pool. In contrast, Wnt^lo cells (with low levels of signaling) are slower cycling and have decreased self-renewing potential. Dual inhibition of Wnt/βcatenin and Notch signaling in GSCs that express high levels of the proneural transcription factor ASCL1 leads to robust neuronal differentiation and inhibits clonogenic potential. Our work identifies new contexts for Wnt modulation for targeting stem cell differentiation and self-renewal in GBM heterogeneity, which deserve further exploration therapeutically.

High rate filtration for local treatment of combined sewer overflow

Combined sewer overflows (CSOs) pollute receiving waters and have a negative impact on ecosystem services. In urban areas rehabilitation of the sewer system to avoid CSOs is associated with high investment costs. Furthermore, not all CSOs can be closed due to the need for hydraulic reliability of the system. Local treatment of CSO with high rate filtration offers an alternative to rehabilitation of the sewer system that is flexible with respect to design and has lower investment cost than separating sewage and storm water runoff. Results from DESSIN, a 4-year EU demonstration project, are presented. The results showed on average 50% removal of particulate matter during CSO events, with higher removal (80%) in the initial first flush period. Other constituents, for example heavy metals, were removed through their association with particles. Potential impacts on ecosystem services in the catchment and the sustainability of the solution were assessed.

Three-Dimensional Nanostructured Architectures Enable Efficient Neural Differentiation of Mesenchymal Stem Cells via Mechanotransduction

Cell morphology and geometry affect cellular processes such as stem cell differentiation, suggesting that these parameters serve as fundamental regulators of biological processes within the cell. Hierarchical architectures featuring micro- and nanotopographical features therefore offer programmable systems for stem cell differentiation. However, a limited number of studies have explored the effects of hierarchical architectures due to the complexity of fabricating systems with rationally tunable micro- and nanostructuring. Here, we report three-dimensional (3D) nanostructured microarchitectures that efficiently regulate the fate of human mesenchymal stem cells (hMSCs). These nanostructured architectures strongly promote cell alignment and efficient neurogenic differentiation where over 85% of hMSCs express microtubule-associated protein 2 (MAP2), a mature neural marker, after 7 days of culture on the nanostructured surface. Remarkably, we found that the surface morphology of nanostructured surface is a key factor that promotes neurogenesis and that highly spiky structures promote more efficient neuronal differentiation. Immunostaining and gene expression profiling revealed significant upregulation of neuronal markers compared to unpatterned surfaces. These findings suggest that the 3D nanostructured microarchitectures can play a critical role in defining stem cell behavior.

Observation of the 1S-2P Lyman-α transition in antihydrogen

In 1906, Theodore Lyman discovered his eponymous series of transitions in the extreme-ultraviolet region of the atomic hydrogen spectrum1,2. The patterns in the hydrogen spectrum helped to establish the emerging theory of quantum mechanics, which we now know governs the world at the atomic scale. Since then, studies involving the Lyman-α line-the 1S-2P transition at a wavelength of 121.6 nanometres-have played an important part in physics and astronomy, as one of the most fundamental atomic transitions in the Universe. For example, this transition has long been used by astronomers studying the intergalactic medium and testing cosmological models via the so-called 'Lyman-α forest'3 of absorption lines at different redshifts. Here we report the observation of the Lyman-α transition in the antihydrogen atom, the antimatter counterpart of hydrogen. Using narrow-line-width, nanosecond-pulsed laser radiation, the 1S-2P transition was excited in magnetically trapped antihydrogen. The transition frequency at a field of 1.033 tesla was determined to be 2,466,051.7 ± 0.12 gigahertz (1σ uncertainty) and agrees with the prediction for hydrogen to a precision of 5 × 10-8. Comparisons of the properties of antihydrogen with those of its well-studied matter equivalent allow precision tests of fundamental symmetries between matter and antimatter. Alongside the ground-state hyperfine4,5 and 1S-2S transitions6,7 recently observed in antihydrogen, the Lyman-α transition will permit laser cooling of antihydrogen8,9, thus providing a cold and dense sample of anti-atoms for precision spectroscopy and gravity measurements10. In addition to the observation of this fundamental transition, this work represents both a decisive technological step towards laser cooling of antihydrogen, and the extension of antimatter spectroscopy to quantum states possessing orbital angular momentum.

Flexible MRI Compatible Brain Probes

The exact localization of signal recording probes or deep stimulation probes by magnetic resonance imaging (MRI) has significant importance in studying and understanding how the brain functions. But the magnetic susceptibility of the probes itself distorts the MRI image and creates error in position measurement. In this paper we propose an MRI compatible flexible probe with magnetic susceptibility that is well matched with the brain tissue. The well-matched magnetic susceptibility of the probe enables high resolution structural and functional MRI even at ultra-high Bfield strengths. The MRI images shows almost zero artifacts around the implanted probe in the phantom tissue.

A Super-Capacitive Pressure Sensor for a Urethral Catheter

Urinary incontinence can be due to neuromuscular or structural problems in either the bladder or the urethra. Urodynamics is often used to analyze the patientspecific cause of urinary incontinence. In urodynamics, a challenging part of the studies involves measurement of the urethral (contact) pressure profile. Here we present an instrumented urethral catheter that is equipped with a novel super-capacitive pressure transducer that is highly sensitive to the applied pressure. A solid ionic electrolyte is used to create a high capacitance device. Through an innovative design the solid electrolyte is made and bounded to a 3d printed soft balloon and then assembled on a 6 Fr urethral catheter. In this paper the design, fabrication and evaluation of the highly-sensitive instrumented catheter's performance are discussed.

Mapping of brain tissue hematocrit in glioma and acute stroke using a dual autoradiography approach

Hematocrit (Hct) determines the ability of blood to carry oxygen. While changes in systemic Hct are known to impact stroke or tumor control, changes in local (tissue) Hct (tHct) induced by these diseases have however received little attention. In this study, we evaluate tHct in acute stroke and in glioma models using a new approach to map tHct across the brain, a dual isotope autoradiography, based on injections of ¹²⁵I-labeled albumin and ^99mTc-lalbeled red blood cells in the same animal. For validation purpose, tHct was mapped in the rat brain (i) under physiological conditions, (ii) following erythropoietin injection, and (iii) following hemodilution. Then, tHct was then mapped in stroke (middle cerebral artery occlusion) and tumor models (9LGS and C6). The mean tHct values observed in healthy brains (tHct = 29 ± 1.3%), were modified as expected by erythropoietin (tHct = 36.7 ± 2.6%) and hemodilution (tHct = 24.2 ± 2.4%). Using the proposed method, we observed a local reduction, spatially heterogeneous, in tHct following acute stroke (tHct = 19.5 ± 2.5%) and in both glioma models (9LGS: tHct = 18.5 ± 2.3%, C6: tHct = 16.1 ± 1.2%). This reduction and this heterogeneity in tHct observed in stroke and glioma raises methodological issues in perfusion imaging techniques where tHct is generally overlooked and could impact therapeutic strategies.

Characterization of the 1S-2S transition in antihydrogen

In 1928, Dirac published an equation 1 that combined quantum mechanics and special relativity. Negative-energy solutions to this equation, rather than being unphysical as initially thought, represented a class of hitherto unobserved and unimagined particles-antimatter. The existence of particles of antimatter was confirmed with the discovery of the positron 2 (or anti-electron) by Anderson in 1932, but it is still unknown why matter, rather than antimatter, survived after the Big Bang. As a result, experimental studies of antimatter3-7, including tests of fundamental symmetries such as charge-parity and charge-parity-time, and searches for evidence of primordial antimatter, such as antihelium nuclei, have high priority in contemporary physics research. The fundamental role of the hydrogen atom in the evolution of the Universe and in the historical development of our understanding of quantum physics makes its antimatter counterpart-the antihydrogen atom-of particular interest. Current standard-model physics requires that hydrogen and antihydrogen have the same energy levels and spectral lines. The laser-driven 1S-2S transition was recently observed 8 in antihydrogen. Here we characterize one of the hyperfine components of this transition using magnetically trapped atoms of antihydrogen and compare it to model calculations for hydrogen in our apparatus. We find that the shape of the spectral line agrees very well with that expected for hydrogen and that the resonance frequency agrees with that in hydrogen to about 5 kilohertz out of 2.5 × 1015 hertz. This is consistent with charge-parity-time invariance at a relative precision of 2 × 10-12-two orders of magnitude more precise than the previous determination 8 -corresponding to an absolute energy sensitivity of 2 × 10-20 GeV.

Erratum: Observation of the hyperfine spectrum of antihydrogen

This corrects the article DOI: 10.1038/nature23446.

Enhanced Control and Reproducibility of Non-Neutral Plasmas

The simultaneous control of the density and particle number of non-neutral plasmas confined in Penning-Malmberg traps is demonstrated. Control is achieved by setting the plasma's density by applying a rotating electric field while simultaneously fixing its axial potential via evaporative cooling. This novel method is particularly useful for stabilizing positron plasmas, as the procedures used to collect positrons from radioactive sources typically yield plasmas with variable densities and particle numbers; it also simplifies optimization studies that require plasma parameter scans. The reproducibility achieved by applying this technique to the positron and electron plasmas used by the ALPHA antihydrogen experiment at CERN, combined with other developments, contributed to a 10-fold increase in the antiatom trapping rate.

Influences for Gender Disparity in Academic Neuroradiology

BACKGROUND AND PURPOSE

There has been extensive interest in promoting gender equality within radiology, a predominately male field. In this study, our aim was to quantify gender representation in neuroradiology faculty rankings and determine any related factors that may contribute to any such disparity.

MATERIALS AND METHODS

We evaluated the academic and administrative faculty members of neuroradiology divisions for all on-line listed programs in the US and Canada. After excluding programs that did not fulfill our selection criteria, we generated a short list of 85 US and 8 Canadian programs. We found 465 faculty members who met the inclusion criteria for our study. We used Elsevier's SCOPUS for gathering the data pertaining to the publications, H-index, citations, and tenure of the productivity of each faculty member.

RESULTS

Gender disparity was insignificant when analyzing academic ranks. There are more men working in neuroimaging relative to women (χ² = 0.46; P = .79). However, gender disparity was highly significant for leadership positions in neuroradiology (χ² = 6.76; P = .009). The median H-index was higher among male faculty members (17.5) versus female faculty members (9). Female faculty members have odds of 0.84 compared with male faculty members of having a higher H-index, adjusting for publications, citations, academic ranks, leadership ranks, and interaction between gender and publications and gender and citations (9).

CONCLUSIONS

Neuroradiology faculty members follow the same male predominance seen in many other specialties of medicine. In this study, issues such as mentoring, role models, opportunities to engage in leadership/research activities, funding opportunities, and mindfulness regarding research productivity are explored.

The feasibility study of 177Lu production in Miniature Neutron Source Reactors using a multi-stage approach in Isfahan, Iran

Miniature neutron source reactors (MNSRs) are among the safest and economic research reactors with potentials to be used for neutron studies. This manuscript explores the feasibility of ¹⁷⁷Lu production in Isfahan MNSR reactor using direct production route. In this study, to assess the specific activity of the produced radioisotope, a simulation was carried out through the MCNPX2.6 code. The simulation was validated by irradiating a lutetium disc-like (99.98 chemical purity) at the thermal neutron flux of 5 × 10¹¹ ncm²s^-1 and an irradiation time of 4min. After the spectrometry of the irradiated sample, the experimental results of ¹⁷⁷Lu production were compared with the simulation results. In addition, factor from the simulation was extracted by replacing it in the related equations in order to calculate specific activity through a multi-stage approach, and by using different irradiation techniques. The results showed that the simulation technique designed in this study is in agreement with the experimental approach (with a difference of approximately 3%). It was also found that the maximum ¹⁷⁷Lu production at the maximum flux and irradiation time allows access to 723.5mCi/g after 27 cycles. Furthermore, the comparison of irradiation techniques showed that increasing the irradiation time is more effective in ¹⁷⁷Lu production efficiency than increasing the number of irradiation cycles. In a way that increasing the irradiation time would postpone the saturation of the productions. On the other hand, it was shown that the choice of an appropriate irradiation technique for ¹⁷⁷Lu production can be economically important in term of the effective fuel consumption in the reactor.

Observation of the hyperfine spectrum of antihydrogen

The observation of hyperfine structure in atomic hydrogen by Rabi and co-workers and the measurement of the zero-field ground-state splitting at the level of seven parts in 10¹³ are important achievements of mid-twentieth-century physics. The work that led to these achievements also provided the first evidence for the anomalous magnetic moment of the electron, inspired Schwinger's relativistic theory of quantum electrodynamics and gave rise to the hydrogen maser, which is a critical component of modern navigation, geo-positioning and very-long-baseline interferometry systems. Research at the Antiproton Decelerator at CERN by the ALPHA collaboration extends these enquiries into the antimatter sector. Recently, tools have been developed that enable studies of the hyperfine structure of antihydrogen-the antimatter counterpart of hydrogen. The goal of such studies is to search for any differences that might exist between this archetypal pair of atoms, and thereby to test the fundamental principles on which quantum field theory is constructed. Magnetic trapping of antihydrogen atoms provides a means of studying them by combining electromagnetic interaction with detection techniques that are unique to antimatter. Here we report the results of a microwave spectroscopy experiment in which we probe the response of antihydrogen over a controlled range of frequencies. The data reveal clear and distinct signatures of two allowed transitions, from which we obtain a direct, magnetic-field-independent measurement of the hyperfine splitting. From a set of trials involving 194 detected atoms, we determine a splitting of 1,420.4 ± 0.5 megahertz, consistent with expectations for atomic hydrogen at the level of four parts in 10⁴. This observation of the detailed behaviour of a quantum transition in an atom of antihydrogen exemplifies tests of fundamental symmetries such as charge-parity-time in antimatter, and the techniques developed here will enable more-precise such tests.

Antihydrogen accumulation for fundamental symmetry tests

Antihydrogen, a positron bound to an antiproton, is the simplest anti-atom. Its structure and properties are expected to mirror those of the hydrogen atom. Prospects for precision comparisons of the two, as tests of fundamental symmetries, are driving a vibrant programme of research. In this regard, a limiting factor in most experiments is the availability of large numbers of cold ground state antihydrogen atoms. Here, we describe how an improved synthesis process results in a maximum rate of 10.5 ± 0.6 atoms trapped and detected per cycle, corresponding to more than an order of magnitude improvement over previous work. Additionally, we demonstrate how detailed control of electron, positron and antiproton plasmas enables repeated formation and trapping of antihydrogen atoms, with the simultaneous retention of atoms produced in previous cycles. We report a record of 54 detected annihilation events from a single release of the trapped anti-atoms accumulated from five consecutive cycles.

Antihydrogen studies are important in testing the fundamental principles of physics but producing antihydrogen in large amounts is challenging. Here the authors demonstrate an efficient and high-precision method for trapping and stacking antihydrogen by using controlled plasma.