# Science

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With open facilities, the Brazilian Synchrotron Light Laboratory (LNLS) annually welcomes about 1200 Brazilian and foreign researchers, committed to more than 400 studies that result in approximately 200 articles published in scientific journals. Check out below some of the many investigations that have benefited from LNLS facilities.

# Alternative to trans fats

Researchers look for substitutes extracted from sunflower oil

The ingestion of lipids, oils and fats, provides essential ingredients to our metabolism. The worries about several cardiovascular diseases caused by the excessive consumption of saturated fats and cholesterol from animal origin, though, have prompted the development of alternative sources of lipids.

# Shedding light on Graphene

Graphene – a thin membrane formed by one or two atom-thick layers of carbon – is considered one of the future building blocks of nanotechnology. Gaining tremendous attention in the last years, graphene and graphene-based material combinations such as graphene/boron nitride find potential applications in optical and opto-electronic devices.

# Traditional Medicine for snakebite treatment

Research can lead to new treatments against envenoming

In traditional and indigenous communities, plants are used for the treatment of a wide variety of diseases and are discovered throughout the years by trial and error, or, more precisely, by live and death.

The active substances in those plants have drawn the interest of the medical and scientific communities, especially for the treatment of neglected tropical diseases, including snakebites for which the mortality rate is higher than that of dengue fever, cholera or Chagas disease.

# Nanostructured Diamonds Using Ultrashort Laser Pulses

The results, by CNPEM researchers, were published in the journal “Scientific Reports” from Nature Group.

A low-cost way to produce nanostructured diamonds from graphite was developed by researchers from the Brazilian Synchrotron Light Laboratory (LNLS), LNNano (Brazilian Nanotechnology National Laboratory) and Ipen (Nuclear and Energy Research Institute). They used ultrafast laser in order to generate a shock wave, which was able to achieve the pressure and temperature levels necessary to synthesize diamond.

# Designing Transporting Membranes with Polymer-Mesoporous Hybrid Materials

The control processes shown here open new paths to pattern transport from exclusion to preconcentration of charged molecules by selecting the appropriate polymerization strategy and polymerization parameters.

Polymer-mesoporous hybrid materials are an exciting class of materials for a wide range of applications, from controlled release to heterogeneous catalysis or solar cells. The charge and isoelectric point of a membrane play a key role in its mesopore accessibility, and through the control of these features, mesoporous materials are able to regulate transport of charged species. Generating hybrid mesoporous materials by surface-initiated polymerization, thus designing specifically transporting membranes, is a fascinating path toward mimicking controlled transport in nature. A versatile route toward hybrid membranes is the use of hybrid inorganic mesoporous-polymeric films. Switching of molecular transport through this type of materials can be achieved by inclusion of organic functions, inclusion of charged polymers by adsorption, or grafting.

# First Demonstration of the Involvement of T4ss in Bacterial Killing

This immediately suggests the hypothesis that, since very few T4SS have been characterized to date, T4SS-mediated bacterial killing may not be restricted to the Xanthomonadaceae family, and may in fact be a more widespread phenomenon.

Citrus canker is a disease that has severe economic impact on the citrus industry worldwide. There are three types of canker, called A, B, and C. The three types have different phenotypes and affect different citrus species. The causative agent for type A is Xanthomonas citri subsp. citri, whose genome sequence was made available in 2002 [1]. Bacterial cells are continuously interacting with other bacterial and eukaryotic cells in a battle for survival. These interactions have driven the evolution of several mechanisms by which they quickly deploy proteinaceous and nucleic acid effectors that manipulate the behaviour of the target organism, often resulting in growth inhibition or death. Distinct among these mechanisms are the type III, type IV and type VI secretion systems (T3SS, T4SS and T6SS, respectively) that are all capable of transferring proteins, and in the case of the T4SS, protein–DNA complexes, directly into neighbouring cells in a contact-dependent manner. All three of these systems have been shown to be able to inject virulence factors into eukaryotic hosts, but only the T6SSs have been shown to deliver lethal toxins into bacterial cells.

# A Hypothesis to Reconcile the Physical and Chemical Unfolding of Proteins

These observations open up possibilities for the study of protein folding and provide a new interpretation to explain the nature of the cooperative behavior of proteins during folding reactions.

It is known that proteins are far from equilibrium during folding reactions, and they undergo a wide range of conformational states to reach the global folding minimum. Various physical and chemical strategies, such as the use of high temperature, high pressure, protonation, altered ionic strength, and harsh de- naturants, are commonly used to disturb folding species to promote the formation of rarely observed folding intermediates. From the thermodynamic point of view, any perturbing agent affecting protein folding is controlled by Le Chatelier’s principle. For instance, increasing the concentration of urea shifts the folding equilibrium toward the unfolded state because of the increased preferential binding of urea to this state. In the case of pressure, the smaller volume of the unfolded state is favored at high pressure because it only affects the volumetric properties of the molecule.

# New Method to Produce Compact Core-Shell Structures of Silver Surrounded by Magnetite

The studies of the size, structure and magnetic properties of the multifunctional brick-like $\rm Ag@Fe_3O_4$ NPs obtained reveal them as possible candidates for advanced medical purposes.

Nanotechnology presents a very fast growth owing to a vast number of applications. In medicine, for example, it is possible to envisage a strong improvement in the efficiency of the magnetic resonance imaging or in the development of non-conventional diagnostics or therapies. The pace of development of the area is strongly dependent on the improvement of synthesis routes, which would allow producing, in a controlled way, new materials capable to act in the intracellular environment.

# Silica-Antibiotic Nanoparticles: Overcoming Bacterial Resistance with Low Cytotoxicity

The authors have demonstrated the effective biological activity of a noncomplex nanomaterial against susceptible and antibiotic-resistant bacteria without significant cytotoxicity.

Infections and several diseases caused by resistant micro-organisms in which the conventional treatment often fails result in prolonged illness and greater risks of death. The inappropriate and irrational use of antibiotics and antimicrobial drugs can lead to resistant microorganisms and provide them with favorable conditions to emerge, spread, and persist. According to the World Health Organization (WHO), a high percentage of hospital-acquired infections are caused by highly resistant bacteria and 440 000 new cases of multidrug-resistant tuberculosis emerge annually, causing at least 150 000 deaths.

# Design of $\mathbf{LnSbO_4}$ ceramics for luminescent devices

These results reveal that it is possible to tune the emission color of these compounds by changing the chemical environment of the $SbO_4$ matrix.

Lanthanide-containing materials comprise a wide range of scientifically and technologically important compounds. They are chemically designed and produced by using different routes depending on the final target: single crystals, glasses, organic-inorganic hybrids, and ceramics. A huge variety of properties can be obtained depending on the choice of the lanthanide, the host matrices and crystalline structures in which they are inserted, either as a dopant or as self-activated element. Known for possessing rich luminescence properties, lanthanides-containing materials have been used in many technological applications, such as laser materials, flat panel displays, cathode ray tubes, up-conversion devices, white-light emitting diodes, X-Ray scintillators, phosphors, and emitters.