Pictures, Images and Stock Photos

Vatican - August 21, 2009: The Pontifical Swiss Guard is a small force maintained by the Holy See that is responsible for the safety of the Pope, including the security of the Apostolic Palace.

Nicotinamide adenine dinucleotide (NAD) is a coenzyme central to metabolism. Found in all living cells, NAD is called a dinucleotide because it consists of two nucleotides joined through their phosphate groups.

Ushaiqer Heritage Village is a preserved example of the traditional Arab mud brick architecture and a popular tourist destination.

A common non-steroid anti-inflammatory drug

Brussels, Belgium - July 17, 2018: Erected in 1905, this grand monument in a park features a triple arch topped by a bronze sculpture.

Glutathione (GSH) is an antioxidant in plants, animals, fungi, and some bacteria and archaea. White background

3D cartoon model, secondary structure color scheme, PDB 2bjj, white background

The crater at the early morning in December

abal Tuwaiq is a narrow escarpment that cuts through the plateau of Najd in central Arabia, running approximately 800 km from the southern border of Al-Qasim in the north, to the northern edge of the Empty Quarter desert near Wadi ad-Dawasir in the south.

The ruins of the old city of Diriyah lay on either side of the narrow valley known as Wadi Hanifa, which continues southwards through Riyadh and beyond. Consisting almost entirely of mud-brick structures, the ruins are divided into three districts, Ghussaibah, Al-Mulaybeed, and Turaif, set on top of hills overlooking the valley.

The Basilica of Saint-Denis became a place of pilgrimage and the burial place of the French Kings with nearly every king from the 10th to the 18th centuries being buried there, as well as many from previous centuries.

Phenylalanine hydroxylase (PAH) (EC 1.14.16.1) is an enzyme that catalyzes the hydroxylation of the aromatic side-chain of phenylalanine to generate tyrosine. 3D cartoon and Gaussian surface models, chain id color scheme, based on PDB 2pah, white background.

The ruins of the old city of Diriyah lay on either side of the narrow valley known as Wadi Hanifa, which continues southwards through Riyadh and beyond. Consisting almost entirely of mud-brick structures, the ruins are divided into three districts, Ghussaibah, Al-Mulaybeed, and Turaif, set on top of hills overlooking the valley.

Chemical formula, structural formula and 3D ball-and-stick model of the anticancer drug capecitabine, white background

Arginine, also known as l-arginine (symbol Arg or R), is an α-amino acid that is used in the biosynthesis of proteins. It contains an α-amino group, an α-carboxylic acid group, and a side chain consisting of a 3-carbon aliphatic straight chain ending in a guanidino group. 3D ball-and-stick model, white background

Melatonin is a hormone, released primarily by the pineal gland, that regulates the sleep–wake cycle. 3D ball-and-stick model, white background

The restored streets in the Munikh Castle suburbs

3D cartoon model with active center close-up, based on PDB 7ctt, black background

3D cartoon and Gaussian surface models, PDB 4bci, white background

Aldosterone is the main mineralocorticoid steroid hormone produced by the zona glomerulosa of the adrenal cortex in the adrenal gland. It is essential for sodium conservation in the kidney, salivary glands, sweat glands, and colon.

Adenosine triphosphate (ATP) is an organic compound and hydrotrope that provides energy to drive many processes in living cells.

An architectural historical monument and tourist attraction.

3D cartoon model, secondary structure color scheme, PDB 5lb8, white background

Nucleosides are glycosylamines that can be thought of as nucleotides without a phosphate group.

The Basilica of Saint-Denis is a large medieval abbey church in the city of Saint-Denis, now a northern suburb of Paris. The building is of singular importance historically and architecturally as its choir, completed in 1144, shows the first use of all of the elements of Gothic architecture.

Albumin is a family of globular proteins, the most common of which are the serum albumins. All the proteins of the albumin family are water-soluble, moderately soluble in concentrated salt solutions, and experience heat denaturation.

King Faisal Specialist Hospital and Research Centre is one of the leading medical research centers in Saudi Arabia. December 2019.

An archeological site and popular tourist attraction east of Riyadh.

Prions are misfolded proteins with the ability to transmit their misfolded shape onto normal variants of the same protein. They characterize several fatal and transmissible neurodegenerative diseases in humans and many other animals.

3D cartoon model, secondary structure color scheme, PDB 4krf, white background

The University's core campus, located on the Red Sea at Thuwal, is sited on more than 36 square kilometres, encompassing a marine sanctuary, museum, and research facility.

The Basilica of Saint-Denis is a burial place of the French Kings with nearly every king from the 10th to the 18th centuries, as well as many from previous centuries.

A carboxypeptidase is a protease enzyme that hydrolyzes a peptide bond at the carboxy-terminal end of a protein or peptide. 3D cartoon model, secondary structure color scheme, PDB 2v77, white background.

Structure of novel coronavirus spike receptor-binding domain (pink) complexed with its receptor ACE2 (blue), surface modeel, white background

The Faisal's Finger Rock is a natural stand-alone rock about 200 m in height near the Jabal Tuwaiq escarpment, a geological wonder near Riyadh.

The University's core campus, located on the Red Sea at Thuwal, is sited on more than 36 square kilometres, encompassing a marine sanctuary, museum, and research facility.

Dopamine (DA, a contraction of 3,4-dihydroxyphenethylamine) is a hormone and a neurotransmitter that plays several important roles in the brain and body. 3D ball-and-stick model, white background

Naloxone is a medication used to block the effects of opioids, white background

Feglymycin is a 13-residues peptide firstly isolated from Streptomyces. 3D cartoon and Gaussian surface models, based on PDB 1w7r, white background.

The equestrian statue of Peter The Great, a symbol of Saint Petersburg,

The Mosque is the spiritual center of the KAUST community. It is constructed of white marble. The courtyard space around the mosque offers a communal gathering site.

Domesticated Arab camels for sale

A breathtaking rock cliff some 120 km from Riyadh

3D cartoon model, chain id color scheme, based on PDB 4puo, black background.

Cytochrome P450 family 2 subfamily C member 9 is an enzyme protein. The enzyme is involved in metabolism, by oxidation, of both xenobiotics, including drugs, and endogenous compounds, including fatty acids. 3D cartoon model with the differently colored secondary structure elements, white background.

Insulin-like growth factor 1 (IGF-1), also called somatomedin C, is a hormone similar in molecular structure to insulin which plays an important role in childhood growth, and has anabolic effects in adults. 3D cartoon model with differently colored secondary structure elements, white background.

β-Carotene is one of the two most common isomers of the plant photosynthetic pigments, carotenoids.

A nucleosome is the basic structural unit of DNA packaging in eukaryotes. The structure of a nucleosome consists of a segment of DNA wound around eight histone proteins and resembles thread wrapped around a spool. 3D cartoon model, black background.

Structural 2D model and 3D ball-and-stick model of the main male steroid hormone, white background

A famous and popular natural landmark in near Stuart Highway

Sphingosine (2-amino-4-trans-octadecene-1,3-diol) is an 18-carbon amino alcohol with an unsaturated hydrocarbon chain, which forms a primary part of sphingolipids, a class of cell membrane lipids that include sphingomyelin, an important phospholipid.

The crater at the early morning in December

The Basilica of Saint-Denis became a place of pilgrimage and the burial place of the French Kings with nearly every king from the 10th to the 18th centuries being buried there, as well as many from previous centuries.

Huntingtin is a disease gene linked to Huntington's disease, a neurodegenerative disorder characterized by loss of striatal neurons. This is thought to be caused by an expanded, unstable trinucleotide repeat in the huntingtin gene, which translates as a polyglutamine repeat in the protein product. 3D cartoon model, secondary structure color scheme, based on PDB 6yej, white background.

Alfaisal University is a private, nonprofit, research institute of higher education located in Riyadh, Saudi Arabia. Founded in 2002 by the King Faisal Foundation as a nonprofit student-centered university, Alfaisal University opened its doors and admitted its first students in 2008.

Spike glycoprotein homotrimer, a main target for neutralization antibody, to bind its receptor, and mediate membrane fusion and virus entry. Cartoon model, black background.

A view from drone of The Edge of the World (Jebel Fihrayn), an unexpected and dramatic geological wonder in the rocky desert northwest of Riyadh, Saudi Arabia.

γ-Aminobutyric acid, a chief inhibitory neurotransmitter in the mammalian central nervous system, white background

MTR of Hong Kong is usually overcrowded at peak hour, but not during the coronavirus pandemic quarantine. April 2020, Hong Kong.

Jabal Tuwaiq is a narrow escarpment that cuts through the plateau of Najd in central Arabia, running approximately 800 km from the southern border of Al-Qasim in the north, to the northern edge of the Empty Quarter desert near Wadi ad-Dawasir in the south.