A retrospective analysis of COVID-19 diagnosis results obtained by rapid antigen tests and RT-PCR: Implications for disease management.

There is a need for understanding and establishment of the most appropriate testing algorithm for COVID-19 diagnosis in asymptomatic high-risk groups. Here, we present a retrospective analysis of RT-PCR results obtained from 412 cases tested negative for coronavirus disease 2019 (COVID-19) by rapid antigen testing method. Among 178 (43.

Ethyl 6-(6-meth-oxy-naphthalen-2-yl)-4-(naphthalen-2-yl)-2-oxocyclo-hex-3-ene-1-carboxyl-ate.

The title compound, C30H26O4, contains an oxo-cyclo-hexane ring in a distorted half-chair configuration, with disorder of two C atoms in a 0.859 (4):0.141 (4) ratio.

(E)-1-(2,4-Dinitro-phen-yl)-2-(2-fluoro-benzyl-idene)hydrazine.

In the title compound, C(13)H(9)FN(4)O(4), the dihedral angle between the mean planes of the two benzene rings of the nearly planar mol-ecule is 6.6 (9)°. The dihedral angles between the mean planes of the benzene ring and its two attached nitro groups are 6.

(2E)-1-(3-Bromo-phen-yl)-3-(4,5-dimeth-oxy-2-nitro-phen-yl)prop-2-en-1-one.

In the title compound, C(17)H(14)BrNO(5), the dihedral angle between the 3-bromo-substituted benzene ring and the 4,5-dimeth-oxy-2-nitro-phenyl ring is 15.2 (1)°. The dihedral angles between the mean plane of the propenone group and the mean planes of the 3-bromo-substituted benzene and 4,5-dimeth-oxy-2-nitro-phenyl rings are 6.

(1E)-1-(3-Bromo-phen-yl)ethanone 2,4-di-nitro-phenyl-hydrazone.

The title compound, C(14)H(11)BrN(4)O(4), contains 3-bromo-phenyl and 2,4-dinitro-phenyl groups on opposite sides of a hydrazone unit and crystallizes with two mol-ecules in the asymmetric unit. The dihedral angles between the two ring systems in each mol-ecule are 2.0 (1) and 2.

8-Bromo-1,3-diphenyl-2,3-dihydro-1H-naphtho-[1,2-e][1,3]oxazine.

The title compound, C(24)H(18)BrNO, consists of an envelope-configured oxazine ring with a fused 8-bromo-1,3-diphenyl group and two bonded phenyl rings. The dihedral angles between the mean planes of the 8-bromo-1,3-diphenyl and the phenyl rings are 54.5 (6) and 87.

(2E)-1-(2,5-Dichloro-3-thien-yl)-3-(6-meth-oxy-2-naphth-yl)prop-2-en-1-one.

In the title compound, C(18)H(12)Cl(2)O(2)S, the dihedral angle between the thio-phene ring and the naphthalene ring system is 2.13 (4)°. In the crystal, pairs of weak inter-molecular C-H⋯O hydrogen bonds form centrosymmetric dimers.

(2E)-1-(3-Bromo-phen-yl)-3-(6-meth-oxy-2-naphth-yl)prop-2-en-1-one.

In the title compound, C(20)H(15)BrO(2), the prop-2-en-1-one fragment is substanti-ally twisted [C-C-C-O = 23.0 (11)°]. The dihedral angle between the benzene and naphthalene rings is 44.

1-(2,5-Dichloro-3-thien-yl)ethanone: infinite sheets mediated by O⋯Cl halogen bonds.

In the title compound, C(6)H(4)Cl(2)OS, the acetyl group is almost coplanar with the thio-phene ring [dihedral angle = 4.01 (2)°]. In the crystal, short inter-molecular O⋯Cl contacts [2.

(E)-1-(2,5-Dichloro-3-thien-yl)-3-(3,4-dimeth-oxy-phen-yl)prop-2-en-1-one.

In the title compound, C(15)H(12)Cl(2)O(3)S, the prop-2-en-1-one (enone) fragment is almost planar [C-C-C-O = 2.2 (4)°] and it subtends dihedral angles of 11.9 (2) and 11.

Ethyl 4-(2,4-dichloro-phen-yl)-6-(6-meth-oxy-2-naphth-yl)-2-oxocyclo-hex-3-ene-1-carboxyl-ate.

In the title compound, C(26)H(22)Cl(2)O(4), the cyclo-hexenone ring adopts an approximate half-chair conformation, with two C atoms displaced by -0.485 (6) and 0.218 (6) Å from the plane of the other four ring atoms.

(E)-1-(4-Methyl-phen-yl)ethanone [8-(trifluoro-meth-yl)quinolin-4-yl]hydrazone.

In the title compound, C(19)H(16)F(3)N(3), the dihedral angle between the naphthalene and quinoline ring systems is 14.58 (8)°. The hydrazone C-N-N=C-C chain is in an extended conformation and its mean plane is nearly coplanar with the quinoline plane [dihedral angle = 3.

Valyl benzyl ester chloride.

1-benz-yloxy-3-methyl-1-oxobutan-2-aminium chloride), C(12)H(18)NO(2) (+)·Cl(-), the ester group is approximately planar, with a maximum deviation of 0.040 (2) Å from the least-squares plane, and makes a dihedral angle of 28.92 (16)° with the phenyl ring.

2-(4-Methoxy-phen-yl)-6-trifluoro-methyl-1H-pyrrolo[3,2-c]quinoline monohydrate.

In the title compound, C(19)H(13)F(3)N(2)O·H(2)O, the phenyl and pyrroloquinoline ring system are close to coplanar [dihedral angle = 10.94 (4)°]. The meth-oxy group also is almost coplanar with the phenyl ring [5.

(±)-Ethyl 6-(6-meth-oxy-2-naphth-yl)-4-(4-methyl-phen-yl)-2-oxocyclo-hex-3-ene-1-carboxyl-ate.

In the title compound, C(27)H(26)O(4), the dihedral angle between the naphthalene ring system and the benzene ring is 73.10 (5)°. In the crystal, a weak C-H⋯O inter-action occurs.

Ethyl 6-(6-meth-oxy-2-naphth-yl)-2-oxo-4-(2-thien-yl)cyclo-hex-3-ene-1-carboxyl-ate.

The title compound, C(24)H(22)O(4)S, was prepared by reaction between (2E)-3-(6-meth-oxy-2-naphth-yl)-1-(2-thien-yl)prop-2-en-1-one and ethyl acetoacetate. In the crystal, the cyclo-hexenone ring shows a distorted half-chair conformation. The length of the double bond in the cyclohexenone ring [1.

2-Isopropyl-5-methyl-cyclo-hexyl 5-acet-oxy-1,3-oxathiol-ane-2-carboxyl-ate.

In the title compound, C(16)H(26)O(5)S, the oxathiol-ane ring adopts an envelope conformation, with the S atom 0.793 (3) Å out of the mean plane of the remaining four atoms. The cyclo-hexane ring of the menthol fragment adopts an almost ideal chair conformation, with all substituents in the equatorial positions.

3-Methyl-1,2,4-triazolo[3,4-a]phthalazine monohydrate.

In the crystal structure of the title compound, C(10)H(8)N(4)·H(2)O, the organic mol-ecules are approximately planar [maximum deviation from the least-squares plane = 0.041 (2) Å]. Two mol-ecules are connected by two water mol-ecules via O-H⋯N hydrogen bonding into dimers, which are located around centres of inversion.

Proteus syndrome.

A 2½-year-old male child born of a nonconsanguineous marriage with high parental age presented with macrodactyly, dysmorphic features, large disfiguring lipomas, small fibromas, a linear verrucous epidermal naevus and lymphangioma circumscriptum. X-ray of hand revealed macrodystrophia lipomatosa progressiva. A lipoma and lymphangioma circumscriptum were confirmed by histopathology.